Headlight Bright / Dim Malfunction Fix
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From: Maker of Sharp Objects, AL - Roll Tide
St. Jude Donor '10-'11-'12-'13-'14-'15-'16-'17
St. Jude Knife Maker
Headlight Bright / Dim Malfunction Fix
Here is a fix for headlight issues involving headlights that either stay on bright or stay on dim and won't switch between the two.
I had this problem come up all of the sudden, and figured I would try to fix it myself. I used two other threads for help with getting the switch out:
http://forums.corvetteforum.com/c5-t...-a-how-to.html
-And looking at some of the internals:
http://forums.corvetteforum.com/c5-t...f-replace.html
After working with the inside of the switch for the better part of a day, I figured out how the bright / dim function works (I think). The switch must be disassembled, and you will find it is three seperate pieces. The piece
we need to work with is the one which will be furthest away from the arm. The first piece with the arm attached is a mechanical assembly only which has a plunger and a contact with a spring behind it. it is what makes the click you feel and hear when you A: turn the left signal on by pulling the lever down, B: turn the right signal on, by pulling the lever up, C: switch forward to brights, and D: pull backwards to flash your brights. The center (Neutral position you might call it) is dim lights only when the shaft has been rotated to turn the ligthts on. You don't need to do anything to this piece unless you have a malfunction of some sort where the arm will not stay in either the A, B, or C position. D is a momentary flash, so it has no "click".
The center piece is gray and contains a mother load of contacts. These are related to the turn signals I believe. I didn't spend much time there, once I figured out that they were not the contacts in question.
Moving on to the third and final piece, you will see a small white Ring gear. This gear corresponds to the black gear on the end of the arm. When the whole assembly is put together, the arm ring gear rotates this gear and switches contacts that will turn the lights on, raise the lights, and maybe something else I'm not sure of. These contacts are detailed in the thread above and are not the ones in question with the dim / bright issue.
Looking further back behind the white ring gear thing in the piece there is a black plunger looking thing raising up out of the module. This piece contains the contacts in question. See the white arrow / safety pin here:
To get this piece out, simply pull it out with a pair of needle nose pliers or something. The piece will come out as an assembly of actually two pieces, but it will be a unit. CAUTION there is a spring behind it; Don't lose this. It isn't going to really jump out at you because it isn't under a great deal of pressure. Just be sure to keep track of it. You will see a small raised nipple down inside the switch piece housing that the end of this spring rests on when this unit is slid back down into the housing.
Here is the spring from the back side, still inserted into the unit we just pulled out -
In this picture I have shown the contacts from the front side. Note the discoloration on the center contact -
The only thing I can figure here is that the discolored arm and contact corresponds to the dim lights, because it was not making contact, and all I had was brights. Also, the discoloration makes sense because it is the one that will be on for the longest period of time. Most people rarely use their brights, and are on dim most of the time. I would assume the discoloration is because of heat caused by a poor contact issue. This could be caused by several things, and my guesses are: not enough contact area, poor conductivity for whatever reason, bad ground, etc. Whatever the reason, mine had deteriorated to the point where it got so hot it actually melted the plastic around the contact itself, and caused a pool of hot plastic to form under the arm and cool. This prevented the contact from closing all the way, so I had no contact for dim lights. The two arms on the edges looked fine and seemed to close properly, but the center one was in bad shape and would not close. Further adding to the issue, the switch slide that rides on the backside of this, back and fourth on the little tracks has a ramp. You can see it noted as "C" below. It had been melted by the plunger arm attached to the bottom of the contact arm because of heat, rendering it useless.
to fix the issue detailed at "C" below, I used a soldering iron to carefully melt the plastic back into the shape of a ramp, and build it back up where it would actuate the arm correctly again when the arm's plunger was struck by it. turning my atention to the front side, I had to lift the arm to get to the pooled up hardened plastic underneath. I again used my soldering iron and a small razor blade to remove this mound of plastic, so that the arm would not be obstructed.
Now, I created another problem. The arm assembly is riveted to the plastic piece, and you can't remove it. when I bent it up, I bent it too far, and lost the preload it had to maintain the closed position of the contacts. So now, I had to figure out a way to bend this arm where it would remain closed. after some careful needle nose pliers work, I somehow bent it where it would close and hold tension on the contact points. Mission accomplished
So now, when everything is put back together, you might be able to understand how it works. It took me a while to figure it out
Here is the final picture with the points of interest labeled -
In this picture "A" represents a place where melted plastic was found in this center area. This is the backside of the contacts, but still noted because of the other plastic. "B" is the small plunger attached to the bottom of the contact arm. It protrudes through the panel to this bottom side. "C" is the ramp that is supposed to actuate the plunger. It had not been fixed in this picture, and you can see the melted spots on it. "D" is a plastic plunger that prodtrudes through all three pieces of the assembled multifunction switch, and the lever arm being pulled backwards and pushed forwards actually moves this. it is part of the slide which moves on the back of the set of contacts we were working on.
When I finally got the switch back together, I got everything to work again except for the momentary pull that you get by pulling the arm back to "flash your brights". Not sure what or how I lost that, but I'm not worried about it because it isn't a necessity. I can live without that. The problem was that the lights were stuck in bright, and this is now resolved, at least for the time being. A new multifunction switch will cost over $100, so to fix this one and buy some time is good. I do think it will likely fail again though some time, because they are prone to do it.
good luck if you attempt this
I had this problem come up all of the sudden, and figured I would try to fix it myself. I used two other threads for help with getting the switch out:
http://forums.corvetteforum.com/c5-t...-a-how-to.html
-And looking at some of the internals:
http://forums.corvetteforum.com/c5-t...f-replace.html
After working with the inside of the switch for the better part of a day, I figured out how the bright / dim function works (I think). The switch must be disassembled, and you will find it is three seperate pieces. The piece
we need to work with is the one which will be furthest away from the arm. The first piece with the arm attached is a mechanical assembly only which has a plunger and a contact with a spring behind it. it is what makes the click you feel and hear when you A: turn the left signal on by pulling the lever down, B: turn the right signal on, by pulling the lever up, C: switch forward to brights, and D: pull backwards to flash your brights. The center (Neutral position you might call it) is dim lights only when the shaft has been rotated to turn the ligthts on. You don't need to do anything to this piece unless you have a malfunction of some sort where the arm will not stay in either the A, B, or C position. D is a momentary flash, so it has no "click".
The center piece is gray and contains a mother load of contacts. These are related to the turn signals I believe. I didn't spend much time there, once I figured out that they were not the contacts in question.
Moving on to the third and final piece, you will see a small white Ring gear. This gear corresponds to the black gear on the end of the arm. When the whole assembly is put together, the arm ring gear rotates this gear and switches contacts that will turn the lights on, raise the lights, and maybe something else I'm not sure of. These contacts are detailed in the thread above and are not the ones in question with the dim / bright issue.
Looking further back behind the white ring gear thing in the piece there is a black plunger looking thing raising up out of the module. This piece contains the contacts in question. See the white arrow / safety pin here:
To get this piece out, simply pull it out with a pair of needle nose pliers or something. The piece will come out as an assembly of actually two pieces, but it will be a unit. CAUTION there is a spring behind it; Don't lose this. It isn't going to really jump out at you because it isn't under a great deal of pressure. Just be sure to keep track of it. You will see a small raised nipple down inside the switch piece housing that the end of this spring rests on when this unit is slid back down into the housing.
Here is the spring from the back side, still inserted into the unit we just pulled out -
In this picture I have shown the contacts from the front side. Note the discoloration on the center contact -
The only thing I can figure here is that the discolored arm and contact corresponds to the dim lights, because it was not making contact, and all I had was brights. Also, the discoloration makes sense because it is the one that will be on for the longest period of time. Most people rarely use their brights, and are on dim most of the time. I would assume the discoloration is because of heat caused by a poor contact issue. This could be caused by several things, and my guesses are: not enough contact area, poor conductivity for whatever reason, bad ground, etc. Whatever the reason, mine had deteriorated to the point where it got so hot it actually melted the plastic around the contact itself, and caused a pool of hot plastic to form under the arm and cool. This prevented the contact from closing all the way, so I had no contact for dim lights. The two arms on the edges looked fine and seemed to close properly, but the center one was in bad shape and would not close. Further adding to the issue, the switch slide that rides on the backside of this, back and fourth on the little tracks has a ramp. You can see it noted as "C" below. It had been melted by the plunger arm attached to the bottom of the contact arm because of heat, rendering it useless.
to fix the issue detailed at "C" below, I used a soldering iron to carefully melt the plastic back into the shape of a ramp, and build it back up where it would actuate the arm correctly again when the arm's plunger was struck by it. turning my atention to the front side, I had to lift the arm to get to the pooled up hardened plastic underneath. I again used my soldering iron and a small razor blade to remove this mound of plastic, so that the arm would not be obstructed.
Now, I created another problem. The arm assembly is riveted to the plastic piece, and you can't remove it. when I bent it up, I bent it too far, and lost the preload it had to maintain the closed position of the contacts. So now, I had to figure out a way to bend this arm where it would remain closed. after some careful needle nose pliers work, I somehow bent it where it would close and hold tension on the contact points. Mission accomplished
So now, when everything is put back together, you might be able to understand how it works. It took me a while to figure it out
Here is the final picture with the points of interest labeled -
In this picture "A" represents a place where melted plastic was found in this center area. This is the backside of the contacts, but still noted because of the other plastic. "B" is the small plunger attached to the bottom of the contact arm. It protrudes through the panel to this bottom side. "C" is the ramp that is supposed to actuate the plunger. It had not been fixed in this picture, and you can see the melted spots on it. "D" is a plastic plunger that prodtrudes through all three pieces of the assembled multifunction switch, and the lever arm being pulled backwards and pushed forwards actually moves this. it is part of the slide which moves on the back of the set of contacts we were working on.
When I finally got the switch back together, I got everything to work again except for the momentary pull that you get by pulling the arm back to "flash your brights". Not sure what or how I lost that, but I'm not worried about it because it isn't a necessity. I can live without that. The problem was that the lights were stuck in bright, and this is now resolved, at least for the time being. A new multifunction switch will cost over $100, so to fix this one and buy some time is good. I do think it will likely fail again though some time, because they are prone to do it.
good luck if you attempt this
