Another grounding question before I set something on fire... (Page 1/2)
SemperFi18 OCT 03, 03:00 AM
Good evening gentleman, I hope you're endeavors are going well for these frustrating cars we love so dearly.. I'm about 6 months into a pretty in depth rebuild on my 86 2M6.

The light at the end of the tunnel is there, I went to hook up the main terminal wires to the battery and got a little more Sparks than normal of the negative side. Immediately followed by a slight building up electrical noise and a little smoke.. the wire in question appears to be a ground wire going to the c500.

Here's what I think I did, please confirm or deny so I can get this ***** running before winter gets here. Positive went from the battery to the starter, small wire to the terminal block below the connectors. NOW.. the negative small wire went to the chassis, the large one I attached to the AC compresser.. on the compressor. That weird unused threaded hole on the top corner?? I'm assuming I'm wrong here, I know a solid block connection would be best, which I will do tomorrow. (Needed a beer and joint)

What's the best most accessable place to attach that wire? I'm assuming running it on the compressor body is creating too much resistant since the compresser attaches to the bracket (painted) then to the block.. I would have just thought I would have weak electrical and not heating wires. Only had the negative terminal connected for a few seconds, so hopefully not too much damage has been done.

Any info or advice would be greatly appreciated, I really wanna drive this car tomorrow. All I did was a long block stroker kit and replaced all sensors plus other suspension components. Nothing with the harness other than re wrapping and tapping the wire loom wrap(cosmetic only)

Sorry for the lengthy post.. I'm getting at my wits end with this rebuild as I'm sure most of you have. I just need a second thought and idea from another mind to get me going. All other grounds are solid and in correct spots. Just the main one concerns me, mainly with the smoke..

Thanks gentleman, you are the unsung heroes of the car world. Forum gospel at it's best. Winner gets a $25 gift card to your favorite restaurant
olejoedad OCT 03, 08:23 AM
The large battery ground attaches to the head above #1 sparkplug, inboard of the passenger side hingebox.

You have another problem, however, as ground wires should never burn up.

phonedawgz OCT 03, 12:42 PM
Do you have at least one, and preferably two ground straps from the engine to the frame? You should.
SemperFi18 OCT 03, 06:26 PM
I have an update.. it appears the wire that's burning up is the A2 wire on the c500. From what I'm finding is the engine ground connection. My negative terminal is ground directly on the block by the engine strut mount. I have the braided ground to from the deck lid mounted and the dip stick tube mount, so pretty much the block. I'm at a loss. Didn't do anything to the electrical, if anything I have created better grounds than it had

SemperFi18 OCT 03, 07:11 PM
So from what I'm reading it's supposed to be a black wire that goes I into the A2 slot for the engine ground. Mine is not black, it's a light greenish/teal. I've checked all grounds, they seem solid. Immediately when you connect the negative terminal this wire gets hot and begins to melt. No other wires are having issues. Any ideas guys?

If you're looking at the c500 with the bolt facing down, it is the far left row, second pin down. A2 correct?

SemperFi18 OCT 03, 07:12 PM


SemperFi18 OCT 03, 08:31 PM
Okay... I'm getting somewhere. Found that green wire is going to the starter. But I don't think it goes there haha, it's on the main post with the big positive cable.

It's on a round metal post connector with another black wire, it sits right by the starter but must connect to the block. Weird thing is I cut that green wire and the problem goes away, car cranks (forgot to connect the fuel pump connector) but I want to get the electrical solid before I go any further. Anyone else know where that black/light green wire bundle goes down by the starter?
SemperFi18 OCT 03, 08:51 PM
Figured it out
PhatMax OCT 03, 09:32 PM
Do tell what you found. It could help the next guy .
SemperFi18 OCT 03, 11:45 PM
Ended up being the green/black wire bundle that goes to the starter, I had it hooked up on the large terminal. It needs to go through one of the starter bolts as a ground.

I'm still having issues getting the fuel pump to prime, but no more hot wires haha.