purpose of small wire on negative cable

[gdw1591]

Can anyone tell me what the small gauge wire with a connector that is attached to the negative battery cable is for? This is on a1988 BII. When it is disconnected the engine stops running. I sometime get a flickering or solid battery/charging light on the dashboard. When the light is on solid and this wire is wiggled, the light flickers. I have cleaned this connector and taped it up to keep it solidly connected and prevent moisture intrusion. When I had the charging system tested, no problems found.
Thanks.

 

[master hec0]

I checked my Chilton book and I didn't see anything about the 2nd wire in any detail. its obviously a ground. just don't play with it and maybe get a new terminal and you should be fine my 87 b2 also has it.

 

[7.5L_STX]

isnt it the frame ground??

on my 89, the big wire went to the block and the little one went to the frame.

 

[BRUTUS_T_HOG]

your big batt cable must have a very bad connection, check for a good connection to the engine block.

the little one usually attaches to the body to ground the body

 

[kunar]

the little one with a connector i was told is for the computer... its kinda important haha

 

[gdw1591]

I heard it was for the computer also, but I wanted to confirm. When disconnected with the engine running, the engine immediately stopped. I had already cleaned and tighten the negative cable to the block, which as another ground cable attached and the same block position.
Thanks.

 

[ldbill39]

According to the factory repair manual, there should be three wires coming off of the negative cable. The main cable which connects to the frame, and then to the engine. A smaller cable (about 10ga), which connects to the front core support, as the body ground. The last wire has a plug about 6 inches down, and then goes into the harness, this wire goes to the computer. Make sure all connections are clean and tight, as you will experience odd electrical disturbances if they aren't. Hope that answers your question. I might be able to get a copy of that page up here if you need it.

 

[adsm08]

There are two, one is a secondary systems ground, one is the PCM's main ground.

 

[Robert_1967]

My 88 ranger has three, the main heavy cable goes to the frame, and to the engine block, one goes to the rad support, the other goes into the wiring harness, that one came loose once and my engine died, it goes to the computer.

Robert

 

[kimcrwbr1]

It`s ground to comp you should also clean all your other grounds also engine to chassis and computer grounds and coil take them apart sand them and put them back together. I always add a wire from the battery connector to the chassis if it doesn`t already have one same guage solder and shrink wrap if you can.

 

[evolveleven]

Cleaning up battery to ECU connection

Can i cut out the crappy connection that goes from negative terminal into the harness and put a solid connection in? Or is it some sort of regulator?

 

[broncobuckinaround]

i have three grounds on my 86 b2. like the manual says. one to the frame one to the block and one to the connector.

 

[adsm08]

Can i cut out the crappy connection that goes from negative terminal into the harness and put a solid connection in? Or is it some sort of regulator?

You can hardwire the PCM connection if you wish, but I wouldn't as it would mean cutting into the vehicle harness every time the negative battery cable needs to be replaced.

 

[broncobuckinaround]

i noticed my third negative was sottered. the one that connects to the computer. crappy sotter if you ask me. i plan to re-do all the grounds.

 

[PetesPonies]

solder