Corvette C4 Headlight Motor Troubleshooting and Repair
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- Опубліковано 7 вер 2024
- Watch me describe the pop up headlight motors installed on 1963-2004 Corvettes. This is the 1984 - 1987 style motor that I disassemble to show the inner workings of it and how it functions.
To see more of my corvette how to videos -
• VetteSource - Corvette...
#howto #diy #vettesource
Great info covering the headlight motor / gears. Saved me lots of $ on my 01
Hey Robert, glad to hear is was helpful👍
Thanks buddy
No problem👍
Good stuff, appreciate u as a resource.
Hey Jeff, thanks. Happy to do it👍.
Very informative video thank you
Glad you enjoyed it👍.
Currently having problems with my driver side headlight on my 87. Both lights would flip up and work but the next day the drivers side wouldnt flip and the light wants to turn on but it is in a dim light state. And solution to what it could be?
My first thought is a ground issue with the front harness. Look at the frame rail on both sides near the horn. You will G101 and G102, which a black wire screwed directly to the rail with a natural 10MM course thread bolt. Try a removal and clean up and see what happens. If that doesn't do the trick, you may have some problems with the isolation relay mounted inside the front inner fenderwell. Let me know how it goes👍.
I have a 1986. The passenger wont pop up but it will close. So I took it off. Plugged it in on the driver side and works just fine opens and closes. Motor,Gears are perfect. What could it be. Bad wire. Or fuse
Most likely it's the relay located in the relay box that is mounted in the left front inner fenderwell. It will have a rectangular shaped plastic cover mounted to a metal plate. Once the cover is removed you will see the 3 relays underneath. Try switching the relays between the individual harnesses to isolate the one that is the problem. Let me know how it goes👍.
*Please Help!*
My Dads 93 Corvette: When he turns the car off it makes these clicking/clonking sounds once per second for 5 seconds and the headlights are already closed. He thinks the headlight motor is trying to close the headlights when they already are closed.
Any thoughts? What is happening, why, and how is it fixed?
The noise you are hearing is the worm gears still spinning inside the housing. This happens because the nylon drive gear or plastic pellets in the gear are disintegrating and allowing the worm gear to keep spinning after it reaches the bumper stops. I describe this in greater detail in this video -
ua-cam.com/video/kuojuwqq2go/v-deo.html
Let me know if you need anything else.
Hi my problem is 1989 left side headlight is like1/2 to complete opening so the lights hit the right in front of the car so my light is limited to safely see ahead any suggestions ? Thank you in advance
Sounds like the headlight capsule assembly has become misaligned with the hood. I would suggest taking the upper headlight housing off and manually raise and lower the headlight to see what's going on. Let me know how it goes👍.
Great video 👍🏼
Hey Anthony, thanks for the feedback. Glad it was helpful👍
Thanks for the detailed breakdown on the motor assembly. My 91 Vette passenger side light opens half way. I can get it to fully open if I turn the light switch on and off several times. After watching your vid I suspect the gear might be stripped in a few places but it was replaced with a metal gear about 2 years ago. Any other things I should check before dismantling the unit?
One of the problems with the replacement metal gears is that they are heavier than the original OEM plastic gear. With the additional weight, the worm gear tends to strip out from the strain of spinning the metal gear. Unfortunately you will most likely need to tear into the motor to see exactly what is going on. For the later 88-96 style headlight motors I have another video here -
ua-cam.com/video/kuojuwqq2go/v-deo.html
It details the disassembly of the these headlight motors. You can also see the gear mechanism and how it works. Thanks for watching and let me know if you need anything else 👍
I had a similar issue. The plastic bumps were worn and causing the headlights to open halfway and close immediately. Check out videos on headlight bumps. Really easy fix
Dear if i close the head light one close good the other close and still make click sound like it still spining...what u think it is?
Most likely the teeth of the drive gear are stripped and on the way to complete failure. Unfortunately it will require a teardown to inspect for damage.
Has anyone found an official troubleshooting sequence for C4 headlamp issues? My 85 is being a pain and needs help.
The best resource is the Factory Electrical Troubleshooting Manual, but now that you mention it might be a good video for me to put together.
Great video! I had an issue of no power to my drivers side light motor. I found a break in the green wire and repaired it. Bench testing motor, I get rotation in both directions by switching polarity. When reinstalled, it will only close. When light switch pulled, only pass side opens. Motor plugged in and motor not hooked up to assembly, it spins continuously in one direction and when light switch pulled it stops completely and doesn't change direction. Thoughts? Thanks in advance.
Hey Joe, thanks for the comments👍. Have you checked the headlight relay box yet? My thought would be the center relay among the 3. That's the isolation relay that reverses the polarity to make the motor spin the other direction. Let me know how it works out👍.
I just bought a 1986 Vette a few days ago and I knew there was problems. But the lights didn’t flip up or down they were stuck. I then noticed the wires were unplugged from the connector. The drivers side I can’t find where to connect it at all. And the passenger side the part to connect it to is cut. So what do I do? I’m fairly new to working on cars
On the inner droverside fender there should be a rectangular box with three relays inside. The connectors for the headlight motors originate from there. Check and see if the box is still there and let me know. I'll try to walk you through it.
I need to know how the drive comes off and goes back on .on a 1984 vette can you help me out
See answer below on your second comment👍
My right side motor wont close unless i unplug the connector wait a few seconds... Plug it back in and then It will go down? Same for up or open. Ill turn my light switch on and it will turn over open. But i shut the light switch off and the light go out but the motor stay open
Until i unplug wait a few seconds... Plug it back in then it wil go close... Any feed will help thank u much.
Sounds like you have a relay issue going on. If you look in the front inner wheelwell area next to the evap canister you'll see a rectangular box that houses the three relays. One is for left, one for right, and the third is an isolation to reverse polarity. I would recommend starting out by unplugging individually to see if that has an effect on the operation of the motors. Also, ebay is a good source for the factory service manual, and it has an excellent electrical diagram troubleshooting section. Let me know if you need anything else👍.
I have a issue, it’s a electrical issue. I have a 86 vette and im trying to figure out what the issue is with my right head light motor, I had it taken out but it’s not working when I tested it, I cleaned up the electrical points as well as I could but still nothing. Nothing is broken but there was carbon or burnt batter inside the motor when I fist opened it. Help?
So when you hook it up to an independent 12 volt power source like I did in the video, it won't function at all?
Nope, not at all. Im gonna try and fiddle with it again but if it doesn’t work. Im gonna have to buy a rebuild.
Gotcha, let me know how it turns out.
good video my problem is that when I hook the batt back up to my stored Vette one of the motors run on its own and then when i try to open the lights they dont open all the way or close all the way. this is a 1989 with 20,000 day time miles on it for the most part
could be a couple of different things. Even with the lower mileage, the bushings inside the motor housing have probably turned to dust and need to be replaced. You can see me tear into this style of motor in this video -
ua-cam.com/video/kuojuwqq2go/v-deo.html
You also need to verify proper operation of the headlight module which for an 89 will be located inside the front left inner fenderwell in front of the tire
Hi, ,, why does one side of pop out light stays open, u close it manual and the soonest u plug it it pops open again and stays open,,? Thx
Based on both your comments, you may be having a problem with the isolation or the switching relays in the headlight relay box. It is attached to the left front inner fenderwell. For identification purposes, it is a plastic over a metal plate with three relays attached to it. You will see the green and gray headlight motor wiring running from the relays to the headlight motors. I would start troubleshooting there first. Let me know if you need any additional information.
@@VetteSource thank you for ur quick response,,,, I'll will check the relay tonight I will let u know how it went,, I appreciate it,, I hope it is what u says ,,,! Thx again and keep making videos every body can use this kind of videos,, thx again,,!
No problem, glad to do it👍
Thanks for the video. I have a 1986 Vette that has just developed a headlight problem for the first time. The left headlight works fine, but the right headlight is not rotating fully to the correct position. I suspect I have the very problem you described in your video, but I’m not sure. I don’t have the diagnostic equipment you have, so I’m not 100% certain it’s the same problem. I was wondering if this could be a DIY Project to maybe change out the gears, or should I seek professional help? I do not have much experience under the hood, but if it’s simple to remove and replace the motor, I may be able to do it. I would appreciate any advice.
Thanks.
Larry
Hi Larry, I would say a DIYer could take care of it, just take it slow and easy and you'll make it through. You can do a visual inspection without the diagnostic tools I had in the video, they just tend to make the job a bit easier. Let me know if you need anything else👍.
@@VetteSource Thanks for the response. One last question. I went to Mid America to buy the metal replacement gear, but they recommend that gear for 1988 thru 1996 Model Years only. They recommend a new or rebuilt motor for 1986 models. Shouldn’t I be able to use the same gear on the 86 model and not have to replace the whole motor?
No, the gear is a different diameter, so you will need the gear set for 84-87 style motors. Stay away from the bronze gearsets, as the added weight does more harm than good to the electric motor part of the assembly.
@@VetteSource Thanks again for all your help. I found the gears on Amazon. Take Care.
Great, good to hear👍.
Great video man
Thanks for the feedback, glad you enjoyed it!
The passenger side headlight on my 1990 C4 Vette gets stuck halfway- but works fine when the hood is up. Would this be a bushing issue? motor issue? gear issue?
Thanks for the help!
Hi Jeff, first thing I would check before going any deeper is to ensure the headlight assembly isn't hanging up on any wiring, loose fasteners, or other components that have come loose and are causing the assembly to bind up when making the flip from closed to open. There is very little room in that space when the good is closed, and you'd be surprised how easily one small piece can become misaligned and gum up the works.
Check that out and get back to me if it's all OK and I will send you some additional troubleshooting information.
My passenger side on my 90 is knocking. I’m thinking bushings are bad and not the gears. If it’s the gears it shouldn’t knock it would just grind correct?
Yep, most likely the bushings. You have the later style motor with the small gear and nylon bushings. I cover the repair of these headlight motors in this video -
ua-cam.com/video/kuojuwqq2go/v-deo.html
My right motor will only close if I turn the knob a small bit. I have replaced the relays. Any ideas before I go into the motor?
If you have replaced the relays it will be necessary to remove the headlight motor and dismantle it for inspection at this point. More than likely you have a problem with the driven gear(grey in color) being stripped out or having worn out rubber insulators in the drive gear. Let me know how it goes and thanks for watching👍
Problem my C4 is the right headlight opens and close great,But my left one just opens and hand crank it closed.I replaced the relay switch for it down fender wall.Do you any other ideas what to do next without pulling the motor assembly out?
If you have tested for power on both terminals of the headlight connector, then I'm afraid your at the point of removal and teardown of the motor to inspect the inner workings. You didn't mention what year you C4 is, but the earlier motors can have issues with the brushes and limit switches that will cause the problems you described.
ok so the long hole in the support is on the bottom or top and one part is support for the motor right
Yes, the slotted part goes over the lower mounting bolts. The other part with have a square cutout for the stud that the 13MM bolt screws on to through the hood hinge bracket.
I need help with 1984 corvette headlight I took it off fixed it put it back in and I forgot how that L shaped bracket goes in can you help me out right side
If you are talking about the small metal motor support bracket, that will attach on top of the lower stud for the main mount bracket, and connect perpendicular to the hood hinge via the removable stud that attaches with a 13MM bolt.
Hi sir do engine wire harness for sale?
What year?
Thanks for the video, I’m wondering if you could help me troubleshoot my headlight. I have an 87 corvette. The left headlight stopped opening consistently (would open about once every 20 pulls on the switch). I suspected that the gears had worn down, so opened up the motor but the gears were actually in good condition without any breaks. However, I did replace them with new bronze gears. But even after that, still having issues. I now have this audible clicking sound that occurs about every 7-8 seconds when I plug in the connection for the motor. When I disconnect the plug, the clicking goes away. The clicking occurs even when I’m not running the car or using the headlights. I’m not sure what to make of it but suspect something electrical. The actual light from the headlight does work without issues. Thanks in advance!
Hey Luke, sorry for the delayed response I've been traveling the last few days. Off the top of head it sounds like you may have an issue with the headlight motor switching relays. Are you familiar with their location?
@@VetteSource thanks for getting back to me! Not sure where that would be located
No problem Luke. The relay box is bolted to the left front inner fender right beside the round vacuum tank reservoir. It will be a rectangular plastic cover that is bolted to a metal plate with three relays mounted on it with grey and green wires coming out of it.
The HVAC in my 96 C4 wants to blow out of the defrost registers instead of the those in the dash. Assume that whatever operates the louvers is malfunctioning. Any tips? Thanks in advance.
Hey John,
Assuming you have the C68 electronic a/c controls, most likely the a/c programmer has gone bad and will need replaced. It is mounted above the gas pedal in a not so great location, and has the vacuum tubes running into it. There is a way using the buttons to force the ac controller into diagnostic mode, but I don't have the sequence here in front of me. It will display trouble codes so you can pinpoint where the problem is originating from. The factory service has the procedure explained in greater detail
@@VetteSource i found that the gm hvac check valve was deteriorated with one output completely unconnected. So that was definitely a defect that is now corrected. Wondering in the shutters are stuck shut now
Thats good to hear you got that problem squared away.. It's possible you have a problem with the shutter actuators, but all roads lead back to the programmer since the vacuum signal originates from there and sent to the individual actuators depending on which direction you want the air to go.
My 84 Corvette driver's side opens and closes, but on the closing part after it does it's full cycle it keeps grinding and won't stop, unless I unplug the connectors..so what do u recommend bfor I pull it apart
Unfortunately it sounds like your internal limit switch is not functioning properly. You will have to remove the motor from the headlight assembly and take it apart as shown in the video to take a look at the electrical part of the motor. You may be able to find a new limit switch, but in some cases it is just easier to replace the entire motor assembly.
@@VetteSource hi,, I have the same problem, I replace the motor and is doing the same thing, I tryed it the new one on the other side where is working correctly and the motors I bought do the same thing, on the good side , it opens and closes perfectly,, but again,, I keep putting the good motors on the good side and they do the same thing, in both sides,, what can it b,, thx
See my reply to your other comment.
It’s your gears…
On my 87 the drivers side is malfunctioning. Doesn't pop up unless I turn the knob on the motor a little. Sometimes it will go up. I hear it making a grinding noise when I turn the knob which means its getting power. What is malfunctioning? Want to get parts before I start.
Sounds like you are dealing with stripped gears. I would recommend buying the gear set of both small and big gear. It will have the pieces you need to rebuild the motor. Thanks for watching👍
@@VetteSource Got it apart. No stripped gears. I did the electrical test. Both ways. Motor does not spin. I have 2 amp. 10 amp and 50 amp. I tried it on 10 amp. Nothing. When I turn the knob by hand I hear a grinding noise in the magnet . Brushes look fine. Can I get a new motor to drop in or whole new unit?
@@randallfox4265 not sure if they are still supplying just the electric motor part of the assembly, so you may be better off with a new motor.
@@VetteSource I took some brake cleaner. carefully cleaned the magnet and blew it out. Motor now works when i plug it in to the connection on the car. It spins continuously. I can't get ti to work with the battery charger. Makes no sense. Amps not enough?
Possibly, but it's worth checking the limit switch to make sure the power is getting all the way through to the windings. It is located right in front of the windings where the grey and green wire terminate
Just had a problem with my passenger side headlight come up after I bought it on eBay 2 weeks ago. The headlight doesn’t want to turn at all & I don’t hear anything when I turn the lights on. Don’t want to buy a new relay only for the problem to be the actual headlight. It’s a 3 pin connector on a 1984 corvette.
Best way to test the motor while it's on the car is to run a 12V and ground jumper wire directly to the headlight motor connector. You can reverse positions of the two wires to see if it will spin in either direction. If no response, then you've confirmed it's the motor. Let me know if you need any more information👍.
@@VetteSource I’ve never using a little voltmeter tool to check voltage.. if I buy one at autozone can I test to see which of the 3 connectors are bad while the car is running? And about the ground jumper wire would I put it directly back in the connector 🤔 I’m young & would like to learn 😀
Sure, you can use the multimeter to test for 12V on the male connector at the forward lamp harness.
To test the motor directly, just us a double alligator clip on the female connector terminals on the headlight motor side, one connected to a 12V source and the other to a good ground. If the motor is still functional, it will spin over immediately.
My light motors continues to click for a few seconds after they retract. Is that a mechanical or electrical problem - do you think?
The clicking your hearing is usually the nylon bearings or gears in the early stages of failure as they slowly strip out or turn into a powdery dust. Unfortunately not much you can do except crack them open for a closer look.
@@VetteSource thank you. I plan on taking the motors apart over the winter. There are some good videos. Hope I can get them open without breaking a bolt. Thx
No problem, anytime.
how did you take the motor off the headlight and put it back on
There is a 13mm nut on the end of the steel shaft coming out of the end of the motor that secures it to the main headlight housing. When you pull the upper body colored bezel off you should be able to see it.👍
Very late to the party 😂 but I recently bought an 87 c4. The issue I'm having is the motor will work to close the headlights, however the motors will not switch to open. Could this be the isolation relay has gone out or does it sound like bad wiring? Some wiring has been messed with by the previous owner so I'm not ruling bad wiring out. Thank you so much the video.
👍
@VetteSource does it sounds like a bad relay or bad wiring?
Sorry, didn't mean to not respond. Sounds like the isolation relay, but I wouldn't rule out the internal limit switch located inside the motor.
@@VetteSource I was able to find that it was the isolation relay. Ordered a new one. Hoping that fixes my problem
Great, glad to hear👍
hey, do you have any idea how much current is flowing? mine do about 6-8 Amps running on the bench...is that the normal amount? greetings
Sounds about right amp wise. You should see 12 volts reversed depending on opening and closing the headlight door. You can apply power and ground to gray and green interchangeably to reverse direction of the motor.
My 92 lights won't go down. I don't hear the motor trying at all. I changed what I thought was the relay for this and nothing changed. Any ideas?
Did you swap out the really box that is bolted to the driver side front inner fender? It will have two plugs with several wires(green/grey) and controls both headlight motors.
@@VetteSource that sounds right.
@@JosephHowes2003 ok, you will need to check 12 volt power to the box itself from the headlight switch. You could have a problem with the switch itself.
@@VetteSource how do I do that?
@@VetteSource do you mean the box holding the headlight motor? So just check up see if 12 volt is getting to the motor?
How do you remove that gear?
To remove the smaller grey gear you will need to press out the pin in the metal drive shaft that turns the headlight. In most cases you can use a long socket and c-clamp or bench vise to remove the pin, then the shaft will slide right through the gear and you can remove it from the housing.
For the large white drive gear, it will come right out with the use of a pick around the edges to gently pry it away from the grey driven gear.
Thanks for watching, and let me know if you need any additional information👍
@@VetteSource THANK YOU!
No problem, glad to do it.
You don’t take the plastic gears
Don't take where? You mean out of the housing?
in your video you don't show how you took it off ,that would b a big help for the right side your showing the left side of an 84 vett
Ok, let me see if I can put together another video this week explaining how to take the motor assembly off the car.
I thought this about the motor, not the gears.........no help for me
Yep. This video specifically deals with gear failure. Maybe in the future I'll have some time to make a video regarding the electrical motor operation. Thanks for the comments👍.