dual battery woes

[scout man]

I wired up my dual batteries today, with an isolator. Everything works great.... except my tail lights, dash lights, and side marker lights. However, my turn signals, headlights, break lights, and accessories still work fine. I cant figure out what it is, because every wire that had power before, has power now. Best I can figure out is that everything that I have never rewired myself... no longer works. Everything functions and charges 100% tho. The wires that were on the alternator output are now on the battery 1 output of the isolator. The accessory wires that used to come off battery 1 are now on a fuse block wired off battery 2. Both batteries are grounded to the engine block. I breifly checked the main fuses under the dash and nothing looked blown, but I was in a hurry and will check again when I can.

I also metered everything.. both batteries are charging off the alternator... the fuse block is putting out power... I dont really know where else to start right now.

I might just need to take a fresh look at it saturday, but for now I am thuroughly puzzled.

[scout man]

I will take pics of the setup when I get a chance, I was in a hurry today. I am pretty happy with how it turned out though, except for the fact that not everything works.

[Brody]

Try running a new power feed to the original main fuse box. I don't know what else to suggest as you really shouldn't have this kind of problem, especially since you merely added a battery.

[Chris]

Also try eliminating the isolator and see if everything works. What are you using as an isolator?

[scout man]

powerline 130 amp. The isolator works though, as both batteries are getting 14v from the alternator.

[sunk]

I may have some time sunday if you would like some help...

[scout man]

cool, I will let you know. I will finally have some time tomorrow to look it over more thoroughly. I will take the volt meter to it and test everything and see where I am and where I am not getting power. I should be able to narrow it down pretty easily that way. If i cant find it though, I will let you know about sunday.

[scout man]

alright, with a few minutes to spend and fresh eyes I found the problem pretty quick. Not saying it makes sense, but I found it...

Basically there was not fuse in the slot for the dash and tail lights. The puzzling part is that there never was a fuse there, and the lights always worked before. So somehow in this dual batttery setup I changed the wiring back to how it was supposed to be, though I have no idea how. So I took the fuse out of the turn signal slot and put it in the tail light slot... and now everything works, including the turn signals. I do think, however, that at some point I rewired the turn signals completely and that is now running through my acc. fuse box.

Pics of my battery setup will be in my build thread in a few minutes. Not that it is anything special looking.

[Mporter]

maaaaagical truck

[scout man]

yea, your not kidding. There are more than a few things on this truck that shouldnt work the way they are, but they do, and a few things that dont work that really should.

[southpaws3]

love old REAL trucks

[Hypoid]

Both batteries are grounded to the engine block. Is there a good ground strap from the block to the body and chassis?

That's been in the back of my mind since I first read it.

[scout man]

yes sir.... i think. Now you have me thinking about it too, but I am pretty sure there is! I know there is one straight from the battery ground to both the engine and the body. I think there is another strap on there too.

[Brody]

Mike has a good point. I know on my heap that I have a lot of redundant grounds.....but the damn thing is really grounded, too. I hate car electrics....

I started doing the overkill on the ground wires when I had a 69 Bronco that I had changed everything out to fiberglass (back in the 80s). I did a full frame off then all the glass body stuff. I had a heck of a time getting everything properly grounded.

[scout man]

yea, I think you guys are right. I will run some more ground wires when I get around to working on the scout again. Things were still a touch weird this weekend, althoug there were no actual problems.

[Speedwagon]

My first thought when reading this, was a bad ground somewhere.

[Brody]

yea, I think you guys are right. I will run some more ground wires when I get around to working on the scout again. Things were still a touch weird this weekend, althoug there were no actual problems.

You might try simply welding some 3/8" bolts to the frame at various points and running grounding straps/cables to them. At least you will know that you have some decent grounds going on that you did and not have to rely on the old factory grounds.

For instance, I use the Blue Torch steel battery boxes for the Optimas I have. I have the boxes grounded, then a redundant ground from the through/mounting bolt grounded again to a weld on bolt on the frame. I did this for both boxes. I also got a grounding terminal from Home Depo and, starting off by running a separate ground from my battery and another to a weld on bolt to the frame, plus another ground to a good part of the body, ground all of my accessories to that.

Aside from the actual grounding box/terminal (cheap, BTW), almost all of the ground wires can be made from battery cable scraps and left over junk in the garage.