First one headlight then the other

[gmhowe]

Went to the store last nite around dusk, pulled the headlight switch and only the driver side light came up, turned off the lights and then ran to the store with the running lights on, came out of the store and tried it again now either one could come up, no noise, no nuthin. Lights come on but neither one will come up. any body have any ideas ?

 

[Baldie88]

The plastic bushings in the gears have turned to dust. Had the same problem with mine till I replaced them. Most Corvette places carry them (MAD, Ecklers, Corvette Central, etc.). Not too hard to replace. Do a search on this website and you'll find lots of how-to's.

Ron
"Baldie88"

 

[c4cruiser]

Each headlamp motor has a small knob at the bottom that allow you ro raise the headlamp buckets. Open the hood and reach down to the bottom of the motor and turn the small knob. If the headlamps raise all the way up with no noises, turn the headlamp switch on then off. If both lamp buckets lower quickly and with no jerking motion, you may have problems with the relays. Each morot has its own relay and there is also an isolation relay.

 

[AdvancedAutoCC]

If you need bushings.....

http://www.corvetteactioncenter.com/forums/showthread.php?p=697494#post697494

 

[Aurora40]

Lights come on but neither one will come up. any body have any ideas ?

Could you hear the motors spinning? If so, sounds like the classic bushing problem. If not, I'd think it might be something else.

 

[gmhowe]

No noise at all, strange that 1 wouldn't work and 15 min later the other one wouldn't work either. gonna replace the on/off switch this afternoon. then see what happens

 

[JonM]

http://www.corvetteactioncenter.com/forums/showthread.php?p=697499#post697499

 

[gmhowe]

Thanx JonM, but shouldn't I still hear the motor(s) turning or making some sort of noise even if the gears are shot ?

 

[Jeb]

I'm leaning towards an electrical problem as opposed to a gear problem.

Do you have voltage to both motors when you pull the "on" switch?

 

[gmhowe]

Haven't had time to check that out, I do know that they both still light up when the switch is pulled

 

[c4cruiser]

This link has a electrical diagnostic routine to check the two headlamp relays and the isolation relay: http://members.shaw.ca/dankai/Headlight%20Doors.pdf

If you do not hear any noise from the motors but can move the buckets with the knob at the bottom of the motor, you may have a relay problem. These relays are not terriblly expensive ($16 from Mid-America).

 

[gmhowe]

I just went out and I can turn the knob to open both

 

[gmhowe]

Thanx for the info C4crusier, if possible could you either email me or post Pages 201-12-B, Even my 85 svc manual doesn't show the location of the relays

 

[gmhowe]

Replaced the headlight switch and now back to the original problem, left one comes up but right one doesn't. Ordering the headlight relay now

 

[AdvancedAutoCC]

Thanx for the info C4crusier, if possible could you either email me or post Pages 201-12-B, Even my 85 svc manual doesn't show the location of the relays

The headlamp relays for 85 are in the LF corner of the wheelhouse area (front of the left wheel, by the carbon canister under a plastic cover). Be very careful, as you can snap off the screws holding the cover on (they're extremely small).

FYI, the 84-87 headlamp motors use a different gear setup than the 88-96, so the bushing fix does not work in this case. Try reseating the relay connectors and another test is to swap the relay connectors and see if the other headlamp now works normally.

Hope this helps you!

 

[gmhowe]

OK replaced the headlight relay and all is ok, the left one started acting up so I cleaned the relay contacts and all better for both. Thanx for all the help guys

 

[cardman138]

Headlight actuator

Went to the store last nite around dusk, pulled the headlight switch and only the driver side light came up, turned off the lights and then ran to the store with the running lights on, came out of the store and tried it again now either one could come up, no noise, no nuthin. Lights come on but neither one will come up. any body have any ideas ?

It's probably the headlight actuator. A little black box that the wiring from the headlights go to. About $100.

 

[c4cruiser]

The headlamp relay/actuator system changed beginning with the 1988 C4 Early C4's used three relays (one relay for each bucket and an isolation relay) 88 and later cars used an sealed electronic actuator. The early relays are around $15 each while the late style is in the $100 range.

Updating to the late style can be done but it's an expensive upgrade as you need different motors, wiring harness, and the actuator. The kit in the Mid-America catalog is $600 :eek