How to locate what is draining the truck battery?
 

Okay, I have a 1983 Diesel Isuzu Pup in fine shape. However, something has been draining the battery. It could be the generator is not generating like it oughter, but if I unhook the battery when I park the truck for any length of time (e few hours, overnight), then the battery is fine and is not even weak. So this is why I am thinking that something may be drawing electricity from the battery even while the truck is off. When I rehook-up the battery, by the way, some dohickey on the right side of the engine clicks, but I don't know exactly what the dohickey is or if it is normal that this click "on" should happen.

How do I take one of these voltmeter/ampmeter thingees and find where electricity is flowing when the truck is off but the battery is connected?

i had the same problem a few years back. the light in the trunk was staying on all the time. also check the glove box.

Can you post a pic of the doohickey? Kinda sounds like the airconditioning idle increasing selonoid that gas engines have. Not familiar with diesels though.

...................Snoozy , go buy yourself a Good 12vdc Test lite. Now , remove the minus terminal on the Battery and insert the testlite betwixt the cable and the minus on the battery terminal . Start pulling fuses , and when the test light goes OUT.....you've found the circuit with the "drain" . From there on it's just a matter finding the particular item that is creating the problem . ..fordy.. :goodjob:

It is the doohicky every time!

Seriously, as far as I can deduce connecting the battery when everything is turned off should not cause any doohickies to make any noise.
The problem might not be with the doohicky itself as it might be controlled by something else. However as suggested by rzrubek post a picture or description so that someone might be able to guess at what it is which may lead to finding the cause.

And all this time I thought that dohickey was a technical term...

Here are pictures of said dohickey:
http://tinypic.com/98vdif.jpg
http://tinypic.com/98ver7.jpg

Fordy -- That was just the directions I need. I'll be borrowing such a metercritter tomorrow and see if I can follow them!

Yikes! That came out HUGE :eek: !

Ya know, that's exactly what my wife......ah forget it, I don't what to get kicked off the forum.

Good luck with your huge dohicky problem.

See ya....

Cabin -- The technical term for what you're alluding to is a Thing o'myBob. (If his name is Robert...) ;)

Okay, those look like two regular doohickies disguised as relays.

Usually they are devices that are used to control a large electrical current by means of a little current. Usually they can be unplugged and these particular 'hickies look like they have caps to pull off.

If it were me I would try to identify what the intended function is, they will control something for example electric radiator fans or the air con clutch. If there is nothing written on them pull one one and put the battery back in then check the vehicle to see what has stopped working!

One easy thing to try is turn off all switches first.

One of my neighbors bought a new car and the battery kept being drained. Turned out to be some stupid Gizmo switch was being left on. Many cars are loaded with them, this one was some light on the dashboard. Can be a light saying a door or whatever is not fully closed. Check the obvious first. The fact the switch is on and there can be some sort of circuit leakage, like a windshield wiper switch, even if the device can't get enough juice to operate. Can be a strange set of facts that is not always techically sensible. Including turning off the radio, etc.

Maybe you have turned something on and don't realize it. One clue is it is probably a very light load, like a very small light bulb or LED display. Usually if it is any load of any size, your battery don't survive the drain downs very long, just a few totally dead cycles kills it.

Lots of things can get a fellow in this life. Doo-hickies, Thing-a-ma-jigs, Gizmos, Discombobulators, Round-2-its, the list is just about endless.

..................Snoozy , that item in the picture looks like some kind of pressure sensing device as it appears to be tied into the braking system . Looks like you have a Pair that also are utilizing those black vaccum lines to control or activate a function of maybe the ABS system if your vehicle gas such . fordy.. :)

Fordy, look at both pics again. I think the device is just a relay. Looking underneath the blue one you will see 3 or 4 wires coming out of a harness. The area is rather cramped and from the pic it is difficult to make a correct call. I haven't a clue as to the relays function but I am surprised that it would click with the doors closed, lights off , and the ignition key removed.

Yeah its a relay and you'd need a schematic to tell exactly what it does but two guesses, fuel pump could be one and as its a diesel it could be the preheater relay. If its clicking on your peheat (assuming it has one and I'd bet lunch it does) your battery will die fast.

...................Yep , it looked like it was tied into the brakes but probably Not . Ross , is guessing correctly , I'm guessing :bow: :eek: :rock: and 1983 is Too early for anykind of ABS system now that I think about it . fordy.. :help: :nerd:

The battery does die fast if I don't unhook it, but as long as the truck is running, it seems okay. If it is the preheat (you mean the glow plug, yes?) , do you think the said dohickies pictured are the problem and the fix would be to replace them? (If they are indeed the culprits?)

When this problem was building up -- it started some months ago and only became dire last week -- the battery light would go on as well as the "Fuel filter needs draining" light when I came to a stoplight, and the engine would make pitiful complaints, but if I gave it some gas, then the warning lights went out, leading me to think maybe I needed to raise the idle. But of course, I never got a Round-to-it (speak of the devil...) Then last week, for no apparent reason, one morning the battery was dead as a doornail, and took quite a long jump to resussitate. (The battery is only one year old.) I have since charged the battery with one of those rechargerdudes, and figured out the trick of unhooking the battery, and the warning lights and pitiful snuffles don't happen anymore. But of course, this is no way to live....

I have an 84 ranger diesel. had glow plug issues in the past. the problem sounds like a glow plug issue. some diesels use what is called after glow. when the engine is not fully up to temp, the glow plugs will cycle off and on at a reduced voltage to maintain proper fuel ignition.I would check something other than the relay. if the battery is going dead, and the relay clicks off and on when the battery is connected and disconnected, the relay is probaly fine. What triggers the relay is the issue. Check coolant sensors and the associated wiring. If a sensor switch is stuck , making the thing think it is always cold, even with the en=gine off, it will cause current draw and kill the battery. Also do as otheres have posted and pull fuses with a test light in line with the disconnected negative terminal.


i bypassed all the factory sensors and made my glow plugs operate manually with a simple toggle switch in the dash that controlled the glow plug relay. Be careful if this is done, turn them on too long and you WILL fry the glow plugs.

I think Mohillbilly is right, it is not the dohicky relay that is at fault but the umgrummit that controls the dohicky relay. This could be as suggested a temperature sensing switch that controlls the glow plugs or it could be another temperature sensor that controls the radiator electric fan but as you didnt mention the fan running all the times maybe not.

However, even if those umgrummits are faulty they would not be able to get to play unless they were being supplied with power and I suspect such things as the radiator fan, the glow plugs, the fuel pump or anything else would not normally come into play until the key is in the 'start', 'run' or at least 'on/acc' position. The same goes for any other switches that may control such dohickies, the advice to double check every thing is turned off is good advice.

I suspect the key switch. Key switches are among the most mischevious of all umgrummits and dohickies because they are subject to mechanical disturbance every time you start the vehicle and more particulary because they are expensive.

The battery light coming on indicates that electrical circuits were taking more power than the alternator was producing at that engine speed which maybe because the glow plugs have been alive all the time and continue to suck ergs even when the engine is running. I dont know how the drain filter bowl sensor works but if it works by monitoring something it might be getting confused by the glow plugs being on though that is a very wide guess on my part.

Precis, subject the 'ignition' switch to intense scrutiny and look for any lash up that any previous owners have made in that area. My suggestion anyway.

Yup, you should be able to isolate your problem into two parts.

1. Those things that need power via the ignition switch to work or have power applied to them at all.

2. Those things that do not need power via the ignition switch to have power applied. This should be a fairly small number and will vary with the age / make and model of the vehicle. Examples headlights, horn, cigarette lighter in many cars.

Your problem is compounded a bit because you probably don't have the book that every fixing type should have for every vehicle they own. Guessing or looking is a poor substitute for being able to look at a electrical schematic. You can go nuts without a schematic and fix it quick with one.

Back to the problem:

If the ignition switch is supplying the mystery load that is draining the battery it can be isolated by disconnecting the connector that supplies power to the ignition switch and steering column. Should be down close to the floor to the left hand side of the footwell for the driver. If you disconnect this connector and the battery doesn't drain down, that tells you the mystery load in question is being supplied via the ignition key or something on the column. Does not neccessarily say the ignition switch is bad. In some cars power is available on the column to certain loads without being routed throught the ignition key, in others all loads go thru the ignition key. Is why the service manual / schematic is so important.

There is one wire in the bundle going up to the steering column that supplies +12 VDC. That is how most folks put a kill switch in the car. They open that connector, on the hood side of the connector find the pin with the +12 VDC and put a switch in series in that wire. You cut it, splice in and wire out a kill switch which is hidden. If the test shows, your problem is being supplied via the steering column / ignition switch power source that can be one practical solution, even if you never find the problem. Plus you have one of the best anti-theft devices around. Turning off that switch effective isolates power. Basically makes it easy to do on a daily basis, without monkeying with the battery cables to turn off power in the car. I install kill switches on my vehicles, is a must have in some areas. On a Dodge Colt, a kill switch does not totally isolate power to the entire steering column. On most older cars it probably does.

If you problem is not in the power going to the steering column then the problem is more difficult. You have to find the offending critter and either replace it or add a switch in series with it. If the offending critter is super expensive and maybe not worth the expense, a cheap isolation switch wired to an easy to use area can be a solution.

First I would isolate the problem to power being supplied via the ignition switch / steering column or not type test by disconnecting that connector for a period and seeing what the results are. Then figuring out what possible solutions can be. You do not always have to find the offending critter.

I had no idea that on the Shop Talk Forum there was such spicy talk as "after glow" -- I'd've visited this forum much sooner just for the thrill... :sing:

Ahem...how does one tell if a sensor switch is stuck?

Ah, but I DO have the Official 1983 Isuzu Pup Service Manual!! :dance: I bought it at Powell's Books in Portland on the way back from buying this very truck in CA. However, when I look at the electrical schematic my eyes cross and I would have a better chance of translating the Quran.

I willl get the metercritter today (Sat) and work on the truck tomorrow. I think indeed there could be a glowplug issue or glowplug relay/sensor issue, because now that I think of it, last summer when I went to get my weaner pigs, the glowplug light wouldn't turn off -- it was sort of faintly glimmering for a good part of the journey, which worried me but then it didn't do that again after I restarted the vehicle for the return trip. Hmmnn.

I did open up the dash and the steering column last week, but I could not see anything obviously amiss to a dope, no corroded wires or anything like that.

You guys are GREAT, by the way!! I really appreciate all your input!!

(PS -- The garbage usually ripening in the back of the truck has always been an excellent anti-theft device, too ;) )

snoozy, since you were able to post such a significant photo above do you think you could scan and post the schemantic?

Ok, locate that connector going to the steering column. Unhook and see if the problem still continues.

Yes, post that schematic, then we can tell what doesn't go thru the ignition switch and can be disconnected for further testing tries.

You really don't need a meter. Probably will confuse you more than help. Need to find various suspect critters and just disconnect them and see when the problem goes away.

I would think that glow plug power should go thru the ignition switch in some manner. Is that how you start it, turn on the key, preheat the fuel / cylinder / whatever for a period and then attempt a start or is there a separate switch somewhere to do the cold prep routine???

Considering this is a diesel truck and we have just two relays all on their lonesome here I suspect those are the only two on the truck, plus of course the starter solenoid.

Assuming there are only two they are most likely starting glow plug and fuel cut off controls.

Snoozy has mentioned a raft of weird things but so far she has not mentioned the truck engine not stopping when turned 'off' hence I suspect the fuel cut off is operating normally. This leaves only the glow plug control.

Then I read this Hmmnn indeed! 'Faintly glimmering' so not fully on. Could be a few of the wires to the steering column switch are a bit chafed and are partially either shorting together or shorting to ground, this might explain some of those other weird things too. So check the wires that head to the steering switch for damage. If there is a connector pull it apart and look for corrosion etc.

Incidently, I notice in the smaller picture that some wires have been added to the fuse box. I wonder what the history of those modifications is?

Okay, guys: Here is a picture of the meter which my friend had. I do not know if it will work for the purpose. Will it? If so, how do I set the dial and wires? He is a civil engineer, which means he couldn't fix his way out of a bucket, but I am in no position to talk as far as this problem is concerned...

Below that are URLs to the scans of the electrical schematics.

So far, by unhooking the two dohickies, I have found that when both are unhooked, the glow plug indicator goes on and seems to function normally, but vehicle won't start (turn over). With the black relay plugged in, the vehicle starts normally. With the blue relay only connected, glowplug indicator lights as usual, but no start. According to the schematic, the black is the starter, the blue is the "Charge warning". That's as far as I have gotten because my almost 6 year old is pestering me mercilessly and I am about to bubblewrap him and mail him somewhere for 12 years....

http://tinypic.com/9b92eh.jpg

Dang it! it didnt' work!! The pic hosting, I mean. I'll repost schematic later....Sorry!

OK, I think we need to know which of the doohickies is the one that 'clicks' when you connect the battery.

Whoops. RIght. Sorry. It's the blue "Charge warning" relay which clicks.

http://tinypic.com/9bbvhj.jpg

Since the image is too small, I have "un-posted" it here on the thread, but maybe you could cut and paste the pics into Photoshop or some other program where you can zoom. If you can zoom, they are quite clear.

http://tinypic.com/9bbvww.jpg

http://tinypic.com/9bbzt1.jpg

My computer will only let me see the details of the first schematic well enough to read it. I am of the opinion that with the ignition switch off that neither relay should click when the battery cable is connected. I can see that if the relay is clicking that it is pulling the glow plug relay heat contacts together causing the glow plugs to draw power. From the ignition start switch you need to determine if either the St or the on positions are hot with the switch in the off position. Set the meter to volts DC and connect the black lead to a good ground on the vehicle. Connect the red lead to the mentioned positions on the start switch and with the switch in the OFF position verify that neither the St or the on position are 12 volts (hot). If so there is voltage present there is a problem in the switch. A simple way to determine is the relay is the origin of the problem you could just disconnect both relays and leave the battery connected and see if the battery discharges.

OK, As far as I can see, the coils of the relays are supplied by the switch and by the controller. When the battery is first connected one relay clicks because it gets supply either via the switch or the controller. However the controller gets its supply via the switch. Therefore, I conclude either the switch is faulty or the wires to the switch have a short circuit.

If you can get to the back of the switch unplug wires but take note of where they came off, then try your battery connection test again.

I am assuming that the circuit has not been monkeyed with, and there are those add-on wires around the fuse box!

You still haven't done the most logical and simple test to divide the problem into two parts. Forget all the techno stuff for a bit.

Just unplug the main connector in the wiring harness going up to the steering column and ignition switch and see if the problem does or does not continue.

That then gives a positive path to continue and focuses in on what to look at next. Can't read but the first schematic. There can be leakage paths with the ignition key off.

If opening the power to the ignition switch cures the problem if can be fixed by addition of a simple Kill Switch. You don't have to run the real problem to ground immediately. But that will sure make it easier, if you want to track down the exact critter causing the problem.

In all troubleshooting you want to cut the overall possible choices in half with each step as the ideal procedure.

Good point Cosmic. Dividing the problem in half and half again is very smart...and I will do that next time. (Matter o'fact, I think that is a smart way to approach all sorts of similar fixit problems, and I thank you for that pithy rule.)

Yesterday evening I unplugged the two dohickey relays but left the battery hooked up, per Agmantoo's suggestion. I now have a dead battery again and am recharging it. (It was not as dead as before, but I was probably starting from a more tired battery before.) I noticed also that the blue dohickey 2 controls/feeds the Charge Warning light & the Fuel Filter Needs Draining light. By the way, since I have been unhooking the battery, the Charge Warning light and the Fuel etc light have not been nagging me, indicating that they were simply doing their job and functioning correctly.

This evening after my day's work, I will see if I can unhook the wiring harness going to the steering column. You do mean down underneath by the driver's pedals, not in the engine compartment, right? Because in the engine compartment I can't see any accessible main highway of wiring going there.

Like a Grand Jury investigation, here are some more oddments of evidence, just in:

I noticed yesterday that both headlamps do not work -- This is a new phenomenon, since they were working up until maybe a few days ago. The brights do work, all other lights function normally. And when I opened up the dash last week, I did not go near that switch, so I don't think I messed up anything at the light switch. (I had managed to unhook the speedometer, but I fixed that... :rolleyes: )

The only reworking of the electricals that I know of, was in the spring of this year, the heater core went kaput, and a mechanoguy replaced it with a generic and wired it so that the heater is always on, but if you don't turn on the fan to move the hot air, you don't notice it except on really hot days, and we don't really have any of those. The problem of the weakening battery and predates that work, but it had never totally drained until last week.

However, after that work, the radio/CD for some reason always completely clears all the tuning presets each and every time I turn off the vehicle, so I have to reset them every time. (That gets tedious.) That was definitely from whatever it was that guy did. The radio power is wired to the cigarette lighter power wire.

The horn stopped working some time ago, but since my previous had a broken horn, too, I got out of the habit of using it and have seemed much more polite on the road than I really am...

The windshield washer pump never worked, but I figure that's because it didn't get a whole lot of use in Mexico, New Mexico, Arizona So CA & Texas, where this truck came from, and just died of boredom. I figure one of these days, I'll replace it.

Yes Snoozy you have a flat battery today even after pulling the relays because the controller dude is still able to suck the ergs via the ignition switch. At least that is my best guess so far.

However, you do seem to have a multitude of electrical problems and some informal modifications. Just assuming the modifications are not causing any problem it does sound like things are a little muddled around about the steering colum/dash area. I would be looking very carefully for chafed wires, modified wires and possibly rodent damage in that area.

I have removed the steering column cover and the heater duct. I have located 2 controllers: one labelled "Controller ERG" and one called "Controller 005". I cannot tell what they control, but perhaps with more tea and perusal of the workshop manual enlightenment will hit me. I have located the main wiring harness coming into the steering column area. I can unhook the wires going just to the ignition. I can unhook the wires plugging into either (or both) controller. I can unhook the entire shebang. There are two wires with pluggy-ends on them looking like they used to have a home somewhere but now are lost & forlorn. Nowhere are there any frayed wires. Nowhere is there rodent damage.

It is hard for me to tell what is "aftermarket modificiation" and what is how it's supposed to be, since to me it all looks rather like it needs spaghetti sauce and some parm.

The manual says that "when the ignition is turned off, all the electrical circuits are de-energized with the exception of the lamp circuits."

Just unhook the one to the ignition switch first. Do the test. If that doesn't do the trick, hook it back up and unhook one of the controllers. Same with the last controller. Eliminate things powered off the steering column one at a time.

If you can eliminate the steering column route or prove it is the culprit, problem will be much easier to solve. Having that radio off the cigarette lighter is asking for trouble. Cigarette lighter should be powered with the ignition key off. Very bad form and practice, should come off the ACC side of the ignition key switch.

Find the battery drain first, worry about the others later. This is starting to sound like a Chinese Gang Bang with many things / potential problems going on a once.

Now that the cigarette lighter thing that come into the picture, adds another layer to things. If something is being powered directly off there, it could very well be the problem. Another check is plug something into the cigarette lighter and prove it is hot with the key off. Should be is on most cars. While doing the other tests can look on the schematic and see where the cigarette lighter gets its power. Probably off that Aux power line with the fuseable link right at the positive terminal of the battery. Get ready to attempt to isolate it, if the steering column checks prove to be negative.

The manual confirms everything should be dead, except lights, with the key 'OFF', my best guess still is a fault in the key switch mechanism. So what I would do next is unplug the wires that go to the kew switch then reconnect the battery and listen for the 'click'.

The loose wire may be significant or they may have been for some acessory that was never fitted. The wires are probably colour coded and the manual should help you find what they are associated with. Hey, they might even be the low beam supply!

OK, I see Cosmic posted his while I was typing that, all good too.

The radio/stereo may have up to three supply wires, it possibly needs continuous power to keep memory settings alive and some (although not this one apparently) require continuous volts as a protection against authorised removal. Then then is a connection off the key switch which is the traditional point to attach a basic radio, connection here mutes the radio while the engine is cranking and stops that horrible rasping noise. Lastly, there may be a power wire from the dash lighting circuits to supply and dim the dial lights.

It is true that unplugging the relevant controller might stop the relay clicking on when the battery is connected but that does not prove anything about the controller as according to the first schematic the controller should be isolated by the switch being off. Not to say the controller is innocent, just that disconnecting it would not prove either way.

I un-hooked the ignition switch, and then connected the battery, and dohickey relay #2 clicked. Is that the test, or do I have to kill the battery to know for sure...?

I unhooked the main wiring harness going to the steering column: relay clicks. I unhooked Controller ERG: relay clicked. I unhooked Controller 005: relay clicked.

What I do now, guys? More tea?

More tea would be good, I must scratch my head somewhat!

Maybe Cosmic can see what is happening?