I have an 86 gt with a 3.4 conversion.
It had a 4 speed muncie with the reverse switch on the shifter. Backup lights worked properly then. I had a Isuzu 5 speed put in (a while ago) the lights stayed on all the time unless I remove the bulbs. I put it off til now to try and resolve it.
Here is what I have done so far:
Bought a new reverse switch. No change.
With reverse switch connected with two completely individual and separate wires from the harness run from the reverse switch over to the C500 Blue C1 and green E1 (per other forum postings/diagrams etc), lights stay on.
Reverse switch not connected.... rev lights stay on. Wires removed from C500..... reverse lights stay on.
Engine harness connection completely removed from the C500....the reverse lights stay on.
I remove the light harness from the C500 ...of course no lights......so I am thinking it is in the light harness. If it was a short then wouldn't the other lights be affected? Don't they share grounds? Doesn't a ground problem mean no lights rather than lights all the time?
I checked the ground under the passenger side wheel well for the light harness and it looks good. I am not great with schematics but I thought there is another ground.... I cannot find it.
I did read that a short with the blue and green wires in the engine harness part that runs by alternator to vss and to rev switch could cause an issue but I removed the two reverse light wires from the C500 and the rev lights stayed on.
It seems like the rev lights are getting power all the time with the key on regardless of revere switch not being connected? Could there be an issue at the fuse box? Nothing has changed there since I have had the car.
Does anyone have an idea of what is going on? I pulled the center console out to see if there was a ground/wire issue with the old connection there. I do not see any wires to connect to for the old switch or anything out of the ordinary. I did remove the bulbs from my ash tray lights as I do not have ash trays. I don't think that would be the issue....would it?
I would put my meter on it to test it but I have no values etc to work with to know what I would be looking at and if they are right or wrong.
Thank you in advance.
Any help would be greatly appreciated as I am losing my mind over this.