Help! How to open headlamp stuck down w/ stripped gear

[averyed]

The driver's side headlamp on my 2000 Coupe is stuck in the down position. I know the gear needs to be replaced, but all the directions to do that start with “open the headlamp.” Mine will not open automatically or by turning the manual knob (I’ve tried both directions dozens of turns). The gear must be totally stripped. Does anyone know how to remove the headlamp assembly without first raising the light? Or have another way to open the light? Thanks in advance.

 

[shark454]

There is a knob (1 1/2 inch diamerer) on the motor assembly. You can rotate this knob to manually raise and lower the headlamp.

 

[averyed]

Thanks, but that's the problem--turning the knob doesn't work either. I need to know if there is a way to remove the whole assembly without first opening the light. Or another way to get to the stripped gear.

 

[shark454]

There are four screws holding the motor assembly to the Corvette. There is a nut/washer holding a flat rod coming from the pop-up assembly that fits on the notched motor shaft. you cam remove this assembly while down with accedd from the top and the bottom of the car.

HTH

 

[leftyvette]

The first time I used the manual headlight knob I also thought it did not work. The knob requires a lot of rotations to move the light a little ways. It moves so slow it can seem to not be working.

 

[shark454]

The first time I used the manual headlight knob I also thought it did not work. The knob requires a lot of rotations to move the light a little ways. It moves so slow it can seem to not be working.

Yes it is a real pain to use and does take for ever.

 

[averyed]

I’ve turned the manual knob hundreds and hundreds of times with no movement whatsoever.

Shark454, what four specific screws are you talking about. I can see 3 different mounting bolts for the headlight motor. One is possibly reachable from the engine compartment with the light down. The 2 other are reachable only from under the car, but there is no access either from the bumper or wheel well. Any suggestions? Do I have to remove the fascia?

Is it possible to remove the pin holding the headlight door, thereby raising the door without removing the motor?

Thanks again.

 

[shark454]

There might only be three. I m not 100%, it's been a few months. The bolts are metric and a 1/4 metric drive socket in your palm is required. The nut holding the retraction arm to the motor shaft is larger if I recall.

No you just need access from underneath and from within the engine. Removing the headlight shroud is helpful but being down, you might not be able to.

Once that nut on the shaft is gone the headlight assembly will be loose. You won't need to mess with the pin. Feel around with your fingers and size the nut and remove it.
Then the arm should come off the shaft (hole is somewhat oval, with parallel flat sides ).

Note the positioning if the arm assembly is is possible to be 180 degrees wrong.

Good Luck!!!

 

[Junkman2008]

Okay, let's get you going in the right direction. You really made this complicated by waiting so long to fix the problem.

You are going to have to access the center nut of the motor from the bottom of the car. You will need a small, 10mm deep socket to remove this nut. Again, it is the nut that is on the center shaft of the motor, and holds the arm of the headlight which raises the light. You will first remove the nut, and then use a flat head screwdriver to pry the arm free that raises the headlight. At that point, you can push the headlight up and start removing the screws that hold the black bezel onto the light. Once that is done, you can then remove the entire headlight of just the motor itself.

Does this make sense?

 

[c5y2k]

Have you tried pulling up on the front of the light while turning the knob? This should help engage a good gear on the worm gear to raise the light.

 

[Junkman2008]

No, it doesn't work that way. The gears do not turn when you tug on the light. You would have to understand how the motor works in order to understand that.

 

[c5y2k]

No, it doesn't work that way. The gears do not turn when you tug on the light. You would have to understand how the motor works in order to understand that.

Trying to ignore what you are implying by you last sentence...this process worked for me when I repaired mine.

 

[Junkman2008]

Trying to ignore what you are implying by you last sentence...this process worked for me when I repaired mine.

Didn't mean anything negative by it. I'm just saying that the gear won't turn if you pull up on the bucket. Maybe you can turn on the light and then try to make the gear engage by lifting the light somehow but when the light is down, you really don't have anything to grab onto. Prying something into the cavity could scratch up the paint so you definitely don't want to do that. You would have to break off a lot of teeth on that gear in order to get the headlight all the way up doing it that way (you would practically have to strip the entire gear).

Looking at the picture below, you can see that if the worm gear has no teeth to grab, it will just spin in place (which is what it does when the gears are broke). So, you have to find some way to turn that center shaft to the point where the headlight gear will engage the worm gear. Or, just remove the lifting arm from the motor and the whole thing can manually be popped up which will allow you to remove it.

 

[shark454]

When I had my motor out, I started to unbolt things and pull apart the motor. DON'T DO THAT! All that does is disassemble the motor into its peices and you'll have one hell of a time putting the armature shaft back into the housing AND compressing the spring contacts at the same time, if you didn't loose any spring, like I did.

For me it was not clear that the gear housing is not meant to be opened and you will need to pry the cover off carefully breaking it away.

FYI
It is my engineering opinnion that the motor assembly was poorly designed! The motor spins for time much longer than needed to close the headlamps. When the motor assembly reaches an end point, it continues to try to spin, against the stops for many seconds. That motor has a lot of torque and over time the gear teeth fatigue and fail.
The designer should have killed the motor somehow when the endpoints were reached, or supply parts that will withstand the force of the motor in this design.

Buy the brass gear!

 

[Junkman2008]

... FYI
It is my engineering opinnion that the motor assembly was poorly designed! The motor spins for time much longer than needed to close the headlamps. When the motor assembly reaches an end point, it continues to try to spin, against the stops for many seconds. That motor has a lot of torque and over time the gear teeth fatigue and fail.
The designer should have killed the motor somehow when the endpoints were reached, or supply parts that will withstand the force of the motor in this design.

Buy the brass gear!

Actually, that IS the way they work.

Battery positive voltage is applied from the headlamp (HDLP) circuit breaker in the instrument panel fuse block to both the coil and switch side of the ALC HDLP relay 44. When the BCM receives this signal it will apply a ground to the coil side of the ALC HDLP relay 44. This energizes the relay, closing the switch, and applies battery positive voltage to the headlamp switch and to the headlamp opening door actuator control module. This actuator allows battery positive voltage from the HDLP MOT LH fuse and HDLP MOT RH fuse in the underhood electrical center to be applied to the headlamp opening door assemblies. The ground circuit is applied from G102.

When the buckets raise and reach the stop point, a signal is immediately sent to kill the power. It does not keep trying to raise the buckets for a period of time as you suggest, unless it never receives the kill power signal. Thus, a broken gear will cause power to continually be applied until the preset "time out" occurs, at which time power is then killed.

There is a good deal of torque put on those nylon gears as you have stated, which is why the brass gears are better for that reason. However, I have heard that the gears are nylon for a reason. They are sometime referred to as "suicide gears" because they are the first to go if some type of power problem occurs where the power is not killed. That would be fine if GM offered the nylon gears for sale but they don't. Since your only choice is to replace the motor or use the brass gears AND there has not been a history of problems with the motors not stopping, the brass gear is the more practical route to go.

 

[shark454]

Actually, that IS the way they work.

Battery positive voltage is applied from the headlamp (HDLP) circuit breaker in the instrument panel fuse block to both the coil and switch side of the ALC HDLP relay 44. When the BCM receives this signal it will apply a ground to the coil side of the ALC HDLP relay 44. This energizes the relay, closing the switch, and applies battery positive voltage to the headlamp switch and to the headlamp opening door actuator control module. This actuator allows battery positive voltage from the HDLP MOT LH fuse and HDLP MOT RH fuse in the underhood electrical center to be applied to the headlamp opening door assemblies. The ground circuit is applied from G102.

When the buckets raise and reach the stop point, a signal is immediately sent to kill the power. It does not keep trying to raise the buckets for a period of time as you suggest, unless it never receives the kill power signal. Thus, a broken gear will cause power to continually be applied until the preset "time out" occurs, at which time power is then killed.

There is a good deal of torque put on those nylon gears as you have stated, which is why the brass gears are better for that reason. However, I have heard that the gears are nylon for a reason. They are sometime referred to as "suicide gears" because they are the first to go if some type of power problem occurs where the power is not killed. That would be fine if GM offered the nylon gears for sale but they don't. Since your only choice is to replace the motor or use the brass gears AND there has not been a history of problems with the motors not stopping, the brass gear is the more practical route to go.

Yes and when the nylon gear goes, since you really cannot get to the gears as a maintenance item, you buy a new motor assembly at " how much?" That's crazy. Be a better engineer and design a system thast doesn't fail by design and if it does fail, you can fix the problem easily.
Yeah the brass gear is a fix but it is not a solution to the problem. The excess torque will still be there.

 

[Junkman2008]

Yes and when the nylon gear goes, since you really cannot get to the gears as a maintenance item, you buy a new motor assembly at " how much?" That's crazy. Be a better engineer and design a system thast doesn't fail by design and if it does fail, you can fix the problem easily.
Yeah the brass gear is a fix but it is not a solution to the problem. The excess torque will still be there.

They did come out with a better design... The C6.

 

[shark454]

They did come out with a better design... The C6.

Hopefully I'll be able to upgrade my 02 headlight motor very soon with a new C6 version!!

 

[Junkman2008]

I like the popups. I've had mine in and out of the car so many times that I feel like I can work on them in my sleep. I did change the look of mine though. I really like them a lot.

 

[shark454]

Very sinister looking!