When manually raising the problematic driver side headlight this morning I actually paid attention to an initial "screwed down too tight" feeling. The manual raise knob which turns counter-clockwise to raise the headlight was really tight at first, then felt free for a couple turns, then started raising the headlight with minimal effort. I compared to the almost always working fine passenger side manual knob. Was not nearly as "tight" when starting up as the driver side knob.
As an experiment when both lights were up and lit I turned them off. Both went down no problem. Then I checked the driver side knob: Same "too tight" resistance again. I turned the knob just far enough to get into the "feels free" zone and switched on the head lights. Both went up!
Is there a mechanical adjustment for how much the headlight travels down? Something I can experiment with? Maybe in the motor/gear assembly?
Originally posted by John W. Tilford: Is there a mechanical adjustment for how much the headlight travels down? Something I can experiment with? Maybe in the motor/gear assembly?
The free versus tight feeling could be because of damaged gears and / or broken up nylon pieces.
It definitely sounds like the nylon (Delrin as VintageNut says) are broken up. They're sacrificial, and they eventually break up, which explains the "free" versus "tight" feeling in the gear. It's easy to fix... you just have to remove the motor, remove the gear plate, clean it out, and replace the nylon pieces (and I think you grease it too, I can't remember).
To all above, late last year I replaced the larger plastic cylinder (with the angled slots on its concave edge) because it had a totally worn away one spot on the edge. As if you'd taken a fine rat tail file the same diameter as the helical drive screw and filed off all the angled slots in that spot. Before that I had to quickly kill power at the battery (closest point I could find at the time) because of a non-stop rapid miniature machine gun sound after I'd turned off the lights and they'd gone down. Sure does seem the motor was running right past the normal higher load stopping point and grinding off the one spot on the edge of the gear.
And now I notice the manual knob was tighter on the driver side when the headlights were down. Which brings me back to the original questions. Is there an adjustment I'm missing for the full down position? Maybe the headlight control module is not properly sensing the increased load on the left headlight when it hits the full down position? Or not reacting properly?
I used Rodney's steel version of the larger cylinder. Also replaced the three plastic 'plugs' although the originals did not seem damaged at all.
Time is money and if its the early gen 1 motors we have no choice but to rebuild but if its the gen 2 (87-88) motors, I just purchase another brand new one for about $80. Easy replacement job and done..
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
New motor with integral gear set fixed the problem. Worked fine over the last couple of days.
Couple of points:
Almost by accident got the Lares brand from Rockauto instead of Cardone. A few bucks cheaper - $85.79 with Indiana tax and shipping = $102.48. "Almost by accident" because I tried to reverse that order so I could get the Cardone instead and couldn't. When the Lares arrived I just put it in. Easy install. The Lares gear box cover uses Phillips head screws, not that I messed with the cover.
As a follow up I took the gearbox cover off the motor I removed. As I remembered, there was Rodney's steel gear with the angled slots around the edge. The three plugs were as perfect as when I installed Rodney's kit. Rodney's grease was more spread of course, but still there. Cover gasket was fine. There was a little in-and-out play on the motor shaft. Not much but noticeable.
I still don't know what caused the left headlight initially intermittent then total failure to raise. I don't care now!
Attention! All you men with mothers take one step forward. Not so fast there Private Smith.
Both headlights were popping right up for a few days after installing the new Rock Auto bought driver side electric motor/gear assembly. Then about two days ago I started the engine one dark morning, clicked the headlight switch on, and nothing. Neither moved. With the engine running and the switch still on I raised the front "hood" and looked - sure enough both headlights were on but facing down. Turned switch off. Hand cranked both up. Turned switch on, lights came on and stayed up. Within a few miles the right headlight popped up about another inch and stayed there after I went over a relatively mild bump. I hadn't cranked it all the way up. When at my destination both headlights went down no problem as always. The up direction has been problematic.
When back home I found a Forum entry from a guy who fixed a similar sometimes-works issue by replacing the headlight switch. (The comments in the entry mentioned a fuse inside the switch.) I had a brand new headlight switch replacement I'd ordered earlier in this saga. Took out the old switch I'd cleaned up earlier but stuck back in place. Took some electronic contact spray cleaner with a small diameter tube attachment and sprayed deep inside each of the female connector openings. Flipped connector up and down a few times with an old towel underneath. Allowed a few more minutes for evaporation to help dry. Installed the shiny new switch. Reconnected battery, started engine, clicked on the new switch . . .
Both headlights popped right up. And have continued to do so. So far. It's wonderful.
All you men with working Fiero headlights take one step forward. Yes, you too, Tilford.
------------------ John W. Tilford
[This message has been edited by John W. Tilford (edited 05-08-2025).]
