1985 C4 Corvette, 35,000 miles
It first started as a broken wire in the headlight motor harness. A little splice work and the motor now runs great.
While having the entire drivers side headlight assembly out, I opened the motor and found the gears in great condition but the rubber shock material inside the large gear were crushed badly. So Inreplaced this shock rubber from the new gear set I had on hand.

I greased the gears and bushings and used RTV to seal the case together. The motor runs when first plugged in and reverses when dash switch is turned on. So all looks and sounds good.

Until I assemble the motor to the headlight bracket and then install the assembly into the hood opening.
The headlight will rotate open fine but when closed it stops about halfway closed and stops. I can push it shut!

So I tear the entire assembly back open and clean RTV and grease out and do it for the second time!
When installed again into the hood the motor opens the headlight fine but when shut off the headlight closes halfway.

Well I waited a few days and tried again making sure I cleaned out RTV and grease and re assembled the entire assembly for the third time. Still same halfway closed.

Now for fourth time I install the new gears into motor, grease and reseal with RTV. Headlight goes up fine but will only close halfway

I still get the headlight to rotate open but when shut off the headlight will only closes halfway?
The old gears and new gears are in great shape and I used a high temp Silicone grease.
I cleaned the contacts on the internal switch and the motor brushes have plenty of material left.
I greased the two brass bushings on motor shaft.

After four tear downs I can do this job in my sleep but why does the headlight only rotate halfway down?
What am I missing? It has to be something simple! But I cannot see it!

So before I order another motor I thought I would ask the C4 wizards out there if they have any ideas?
Going to take a shower and have a few cold ones waiting for any ideas.
Thanks ahead of time

 

Make sure that screw on the side of the housing isn't hitting the hood as the door closes. That's a special low-profile head on that screw. It sounds like you've done all the right things!

 

That would be the headlight shroud Torx screw?
Yep both are still tight.

Had the passenger side torx screw come loose when I took ownership of car.

Motor runs fine and strong when alone outside of assembly.
But when installed in assembly headlight goes up fine but still stalls at halfway going down!

I looked at spacing around the entire assembly and have plenty of room.
Thanks

 

I just swapped the two relays and No Change,
then swapped the isolation relay with a brand new relay No Change.

Will tear it open tomorrow and look at the three contacts inside of motor?
Just read one post where the contacts can just not be square to each side causing intermittent contact?