Ground JC-02
06-21-20, 04:49 PM
#1
Ground JC-02
I was digging through the ground circuits on my 1988 convertible, and had noticed that there was almost a 1/2 volt difference between the battery post and some of the ground wires, most notably the fuel pump circuit. I found and cleaned a few grounds around the trunk area, but that didn't seem to help much, so I started digging through the wiring diagram which led me to JC-02 (guided by threads like this and this)which is a ground junction plug located up behind the instrument cluster. Well... I had assumed that this was similar to JC-01, which is the junction under the trailing spark coils. JC-01 is a connector that plugs into a metal bracket that is bolted to the rear of the driver's side strut tower to give a path to ground. Well... this was not the case, and I hadn't seen it mentioned on here.
As you can see in the picture there, the JC-02 plug does not actually connect to a ground in the same way JC-01 does; it seems to bridge a bunch of individual ground wires to a single, thicker ground wire that leads to... where? There was good continuity between this metal bridge and the ground visible on the red metal bracket, but I don't know if that's just through other ground connections.
Anyway, to try to solve the grounding issues I'd been having, I drilled a hole in the bottom of this bridge to slip part of a wire through, then I soldered that wire to the bridge and connected it back to JC-01, and from there added another ground to the alternator bracket. This seems to have helped, but I think I still need to connect this all the way back to the main ground strap on one of the starter bolts. Ultimately I added another ground running back to the fuel pump ground wire too, which does seem to have helped a bit.
Just thought I'd share this for anyone else trying to chase down grounding problems.
As you can see in the picture there, the JC-02 plug does not actually connect to a ground in the same way JC-01 does; it seems to bridge a bunch of individual ground wires to a single, thicker ground wire that leads to... where? There was good continuity between this metal bridge and the ground visible on the red metal bracket, but I don't know if that's just through other ground connections.
Anyway, to try to solve the grounding issues I'd been having, I drilled a hole in the bottom of this bridge to slip part of a wire through, then I soldered that wire to the bridge and connected it back to JC-01, and from there added another ground to the alternator bracket. This seems to have helped, but I think I still need to connect this all the way back to the main ground strap on one of the starter bolts. Ultimately I added another ground running back to the fuel pump ground wire too, which does seem to have helped a bit.
Just thought I'd share this for anyone else trying to chase down grounding problems.
06-21-20, 09:25 PM
#2
Junior Member
That ground splice pack gets its main ground from an eyelet above the steering column. I think I can actually see it in both pictures you posted. In the first picture, if you look to the left of the cluster connector on the right side, there is an m6 bolt head. That bolt should have 2 ground wires on it and 1 is for that connector.
06-22-20, 09:33 AM
#3
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that connector/ground is a PITA!
06-22-20, 01:07 PM
#4
That ground splice pack gets its main ground from an eyelet above the steering column. I think I can actually see it in both pictures you posted. In the first picture, if you look to the left of the cluster connector on the right side, there is an m6 bolt head. That bolt should have 2 ground wires on it and 1 is for that connector.
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