1987 Jeep Comanche MJ

Been having issues with my Alt. not charging my battery I've been told that this box is used for a dual battery setup. Anyone seen this before. I dont want to run 2 batteries so can i just remove it and run the wires to my battery?

 

Anyone?

 

doesn't look factory to me. and I'm sure someone with more experience will chime in and show you a wiring diagram, but yeah you should be able to pull it out and run wiring from the alt to the battery.

ps. send that my way if u do remove it! haha

 

Not factory.

 

That's after market. It is for running 2 batteries. Ditch it and run yer wires.

 

I suspected it was aftermarket. Thanks guys.

 

yeah, it looks like a battery isolator.

i'd find out what is missing, if it's just a battery, get one just like the one you have, hook it up and you're good for almost any electronic upgrade you want.

 

It has a battery box in the bed used to power fans and a light in the bed cap. Im going to keep it and maybe eventually install it back but right now i just want to get it back on the road.

 

That is indeed a multi battery isolator, which should facilitate in charging BOTH batteries that are connected to it. With that being said, it looks older, and if you're not properly charging your main battery, I'd suggest you bypass it temp to see if this resolves your charging issue. if it does, then the battery isolator has most likely gone bad.

 

alright removed that battery isolator today and connected the 3 leads to my battery terminal connecters. The black wire runs from the stud on back of the alt. im assuming thats a ground so i put it to the ground terminal. The 2 red wires, one from the main harness and the other from the alternator connecter that plugs into the back of the alt. I ran those both to the positive terminal connecter. I then started it up and it still wasnt charging. then I disconnected all the wires and used a multimeter to test if i was getting 14V at any of them...the ground no, wire from the alt connecter and the main harness positive had a ~12V.

Does this system have a voltage regulator? or is my alt. shot?

 

Ummm 87 Manche? There internally regulated. The "stud" is your power wire the 2 smaller wires on your alt are for the ecu and regulator.

 

If by stud you mean that little 10mm gold nut. That's you + charging wire.
The other 2 wire plug at the top are the signal wires for indicator and ecu.

 

Great... so When I tested that wire with the engine running it came up with 0 volts so i'd say the alt. is shot. I love PO janky *** wiring.

 

Or it could of been when you grounded it....

 

Yup that did it im sure, thanks for your help. I'll pick up a new one and hook it up right.