Hello,
I wanted to share something I discovered when diagnosing headlight issues on my 86 GT. The switch on the dash would occasionally activate the driver side motor to raise the headlight but not the passenger side. I am sure this fix could work for the opposite side too. Your motors must be in working order for this to solve the problem, but it worked for me. I had to manually raise them and then unplug that single wire connector next to the motors under the hood to keep them up but they would lower automatically when I plugged that wire back together.
There are contacts behind the instrument cluster that seem to get corrosion. The main culprit for me was the driver side connection behind the speedometer. I pulled the dash apart to get to it but after I cleaned all of the connectors and reinserted them into the cluster both headlights started working perfectly again.
If you are diagnosing an intermittent pop-up motor malfunction or can't get your headlights up raise and lower with the light switch...check your connections to the cluster. Not just the switch connector... I cleaned them off (they had green gunk) on the connections. I was pretty frustrated until I discovered this but they work every time now. Make sure all of the headlight connectors are reconnected under the hood too.
Be careful because the plastic circuit board could be brittle and moves around a bit when removing/inserting the connectors.
Hope this helps...
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Aaron H
1986 Fiero GT 2.8- A dream car of mine since childhood- Stock now, but looking for creative options to upgrade this wonderful car
2000 Caddy Deville- Has the Northstar- possible donor engine
[This message has been edited by Phlebmaster (edited 11-26-2018).]