truck wiring question

[pcdreams]

I've got an old 78 chevy c20 pu and will be pulling a rv behind it. Of course I'm working on wiring up a 7 prong plug. Got most of it figured but..

I need to get a 12v line to the trailer to charge the batteries. obviously, I only want the line to be hot when the truck is running, so as not to drain the truck battery. I'm about ignorant when it comes to understanding this stuff (when reading it).

On the same idea. the truck has a place for 2 batteries. Would I need to (or would it be better to) figure out how to set the two on the truck up then try to run a line? I'm thinking this might give more power, but at the same time it'd be more work for the altenator..

would I need a battery isolator (or 3) .

[tamsam]

Ok I did this once.You need at least 8 ga wire and hook it battery to battery just like jumper cables. If there is any hot rod places around you you can get a cut off switch to put in line between you truck and camper. of course you have to turn it off. This is the simple way. Or you can make it auto with a soliniod. [sp. my meds have finally kicked in]. mount it some where close to you truck battery and wire it inline going to your rv. You know big wire to each of the big post on the sol. Next find a wire from your fuse box that is hot when you turn on the switch. Run this wire to the little post on the sol. If the sol. has 2 small post use the one that makes the sol. click when you touch a hot wire to it. You will have to splice into the wire from the fuse box. Ok breakdown of this hook up. 8 ga wire from battery to one side of sol. 8ga wire from other side of sol to wire going to rv battery wire in plug up for rv. Small wire from fuse box to small post on sol.This should make the rv wire hot when you turn on the switch. I hope you can understand this. Good luck Sam

[radiofish]

On my 1967 and 1969 Ford F-100 pickups, I went with a dual battery system. It uses an isolater placed between the output of the alternator and the vehicle main battery and goes to a 2nd deep cycle battery which is dedicated for my mobile ham radio gear. I used several external 50 amp vehicle circuit breakers placed in line on either side of the battery isolator and near the batteries using 6 gauge braided wire with soldered end ring/ spade connectors.. It is set up with with the standard factory 90 amp alternator, on the 352/ 360 cubic inch V-8 engines.

In wiring for the back of my camper shell or even a trailer (use a seperate large gauge connector, depending on how many Amps being used), I would go along the same lines as Sam described. But I would start my wiring only from the 2nd accessory battery - that way the vehicle battery has no chance to drain from an inadverant load. Plus if things get all FUBAR, you can remove the 2nd battery from the system, and still have your vehicle electrical system uncompromised by a short.

Unless of course the battery isolator itself goes south on you, like one of mine did!!!

I also have fused toggle switches mounted in the cab, which I use to control the electrical load for my mobile ham radio equipment and the stereo gear.