Brake/blinker question.

Brake/blinker question.


Sharpsburg, Georgia
86 CJ,Dana 35, AMC 20, 258 I6, T176, Dana300.
Hey I'm some what new to the forum and have searched to find an answer to my problem. But nothing quite seems to fit, so if I've missed a thread with the answer let me know.

I have an 86 cj that I've had for about 8yrs. It's been sitting for the most part. I recently started goin through the steps to get it back on the road. Only to run into this.... The brake lights and blinkers don't work with the engine running, however I do have running lights. If I disconnect the pos side of the battery with the engine running, the blinkers and brake lights start working. ( I stumbled on to this when checking to see if the alt was charging.) And I have a constant drain on the battery. If I let the jeep sit for a couple days the battery will be dead. (It's a new battery). I recently did the nutter bypass. Wanted to through that out there just in case it has something to do with it. I'm gonna start checking grounds just as soon as I get my Hands on a wiring schematic. Any help/direction would be appreciated.
Thats a weird one.

Like you said, Id find the draw first.

Grounds are usually the cause of unusual power problems. Im guessing you have a situation where a poor ground is making it so that when the engine is running, there isnt enough "room" in the circuit to power the brake and turn signals. When you disconnect the pos cable, you are taking some other items out of the equation and the brake and turn signals can then operate. The ign. switch is in the same position when the engine is running or just key on/engine off so that shouldnt be it.
the brake light /blinker problem is a good one. I do hope you will share the solution with us when you find the problem. I am going to suggest you check the connections on the fuse block. try moving the fuse up and down and see if that restores the circuit. I can't help but think the alternator thing is just a coincidence or perhaps a rise in voltage it caused made the connection in question.

as far as the parasitic drain, I suggest you use an amp meter in line. start at the battery and follow the current.:cool:
The way I have found what is draining the batt is to put a amp meter on the batt then start pulling fuses until you get a change then you know what circuit is the cause and inspect it.
Alright guys here's the latest... I pulled all the light assemblys, cleaned the connections, cleaned the sockets, replaced all the bulbs and put dielectric lube on all proper connectors. All the fuses tested good with a test light, but seeing that it's sat awhile I replaced a few of them and the flashers. When I shut things down sunday night all was working properly.
The battery must have a bad cell because my volt metter was reading 12 or 13 volts coming off the alt. (sorry can't rember the exact reading). I charged the battery for about 20hrs on a matience charge and let it sit for a few days in the jeep with both the pos. and neg. cables disconnected. The volt reading after the "trickle charge" was 13v. After sitting 3 days it dropped to 10. And some change. When I get a new battery I'll check everything out to make sure I don't have a drain.
On a side note does anyone know where I can get a color wiring diagram for my jeep? When I get this sorted out I'm gonna try and eliminate the emissions rats nest of wires I have. I don't have to pass emissions with it now and half the stuff is missing. Thanks for all the help so far.
the $16 one is money well spent, it is 11X17 inches and laminated .:cool:

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