Contemporary parking light / blinker lamp stays on

[SCOBRAC]

I posted this problem once earlier looking for a direction and got some great replies, but I'm still chasing an electrical gremlin in my Contemporary built in 1988. The car has almost 20 years and 23,000 trouble free miles. The last 5 with me. I mention this as there has been no history or systemic issues with the car.

I was out for a nice drive last month, a few hours and a hundred and fifty miles maybe. About half way throught I parked for several hours and I think I left my marker lights on. When I got back to the car and fired it up the ammeter went way over and stayed there for almost 45 minutes and gradually settled down. When I got home I noticed the front left marker light was illuminated in the bright mode, or having both the turn signal and the marker filiments on and would not shut off.

All the lamps work in the car, headlamps, marker lamps brake lamps. The right front and rear blinker operates as it should but the left does not flash front or rear. Not surprizing since the front blinker is already illuminated.

I posted the inquiry here and got a number of good replies icluding grounding issues, lamp and bulb issues, shorting out of lamp sockets, flasher replacenment and lamp socket grounds. I dismantled the turn signal control module and the relays are working as it should, tripping the relays left and right. Both relays seem to be working the same way and have a crisp clean stike between the contacts.

I have been slowly running down the potential causes one by one and have narrowed it down a little. All the grounds are good, (at least the ones I can find) including the grounds at the lamp fixtures everything seems to be as it should be with the exception of the lamps being on. Ive replaced all the bulbs, headlamp swith and the flasher with no change in the problem.

I have seemingly isolated the main source of the problem or perhaps main symptom. There are 2 wires going to the front left turn signal as well as a ground, a solid white wire and a solid green wire. If I disconnect the just solid white wire at the junction under the hood the marker lamp filiment goes off (dimmer of the two filiments). If I disconnect just the green wire both filiments go off.

This suggests to me that the green wire is being fed from a source other than the turn signal control module and is feeding back through the system, and disconnecting it from the lamp shorts the circuit Is this logical? I didn't build this car and to be honest troubleshooting electrical isn't my strong suite.

If you own a Contemporary have you had a similar experience, or even if you have owned another marque and had a similar problem, how did yo fix it. I ask because at this point I am about to start chasing individual wires under the dash and it will be a messy job. Any help would be appreciated.