Repairing balky headlight switch

[Rich]

Our original headlight switch is starting to hang up from time to time. It doesn't spring back after every push in which case it can't be advanced to its next detent position unless I grab the button and pull back on it first.

Minor annoyance for now, but getting worse.

So is it merely a matter of popping the switch apart and lubricating/cleaning? Seems like the spring is still OK; it acts like there is some dirt or interference keeping it from popping back like it used to.

The pushbutton is clear of the surrounding panel - no hangup there. The electrical function is 100% OK.

Yes, I know replacement switches can be bought. I'd like to keep this one working if I can.

So, looking for DIY teardown/rebuild tips for the headlight switch.

[hmcelraft]

I have experienced this problem several times over the years.

The OEM light switch carries all the exterior running-light amperage, except the head lights, and the dash lighting including the "daytime" illumination of the AC panel. The running light amperage is enough to damage the switch (close to 15 amps). You will probably find the switch deformed from heat.

The running lights, or parking lights, are split into left and right. The light switch powers the fuses for the parking lights (Fuses 2 and 8). I installed a relay between the wire from the light switch and the fuses to power the running lights which takes virtually all of the amperage off the light switch. Seemed to fix the problem (20 years on one car of mine). The new switch from DMCH with the relay box and other features will do the same thing with added features - an auto off I believe - and you get a nice wiring diagram to guide you.

[SS Spoiler]

About ten years ago my headlight switch would only work on high beam if I held the button down. It made for some difficult gear shifting
acrobatics. At that point they were no longer available. With nothing to lose I took the switch out and took it apart. Being careful to keep track of where everything goes, I found some melted plastic was jamming up the works. Shaving the melted bits and reassembling the switch it has worked fine ever since. I understand some of the vendors can repair them. [ Watch for flying springs ]


Paul Cerny #2691
Kalispell, MT

[David T]

About ten years ago my headlight switch would only work on high beam if I held the button down. It made for some difficult gear shifting
acrobatics. At that point they were no longer available. With nothing to lose I took the switch out and took it apart. Being careful to keep track of where everything goes, I found some melted plastic was jamming up the works. Shaving the melted bits and reassembling the switch it has worked fine ever since. I understand some of the vendors can repair them. [ Watch for flying springs ]


Paul Cerny #2691
Kalispell, MT

Special T also sells a relay kit to get most of the power off the switch. I think the auto function in DMCH's switch is not working anymore. Fixing a melted switch is a temporary fix. One big reason they melt is because of corrosion problems in the front marker light sockets.

[Rich]

I have experienced this problem several times over the years.... I installed a relay between the wire from the light switch and the fuses to power the running lights which takes virtually all of the amperage off the light switch. Seemed to fix the problem (20 years on one car of mine).

Yes, I have the relay kit on mine, too.

So what did you do to originally fix the problem? Are you saying that adding the relay kit somehow fixed the problem? Or rather that it prevented the problem in the first place?

[dustybarn]

Yes, I have the relay kit on mine, too.

So what did you do to originally fix the problem? Are you saying that adding the relay kit somehow fixed the problem? Or rather that it prevented the problem in the first place?

The problem is that the headlight switch is marginal for the amount of current that it is asked to carry. Although there is a relay for the headlights, the power for the parking lights, license plate lights, dashboard lights, and side marker lights all goes through the headlight switch. Adding a relay for the parking lights significantly reduces the current passing through the switch, and reduces the likelihood that it will melt down.

I went a different direction and switched to LED lamps for everything except the instrument cluster.They use a lot less current.

[Rich]

The problem is that the headlight switch is marginal for the amount of current that it is asked to carry. Although there is a relay for the headlights, the power for the parking lights, license plate lights, dashboard lights, and side marker lights all goes through the headlight switch. Adding a relay for the parking lights significantly reduces the current passing through the switch, and reduces the likelihood that it will melt down.

I went a different direction and switched to LED lamps for everything except the instrument cluster.They use a lot less current.

Understood. As I said in post #5 I already have a relay kit, the one that takes the auxiliary lamp current out of the HL switch so this switch isn't loaded like it was originally. At this point LEDs will not improve the situation but a rebuilt or replacement switch will.

So I want to rebuild/repair the switch if that's feasible and am looking suggestions on the method. Plan B might be to send it to John H. for repair.

So far I have some decent input:

"....I took the switch out and took it apart. Being careful to keep track of where everything goes, I found some melted plastic was jamming up the works. Shaving the melted bits and reassembling the switch it has worked fine ever since."
That may do it.

Any other hints out there?

[dustybarn]

Understood. As I said in post #5 I already have a relay kit, the one that takes the auxiliary lamp current out of the HL switch so this switch isn't loaded like it was originally. At this point LEDs will not improve the situation but a rebuilt or replacement switch will.

So I want to rebuild/repair the switch if that's feasible and am looking suggestions on the method. Plan B might be to send it to John H. for repair.

So far I have some decent input:

"....I took the switch out and took it apart. Being careful to keep track of where everything goes, I found some melted plastic was jamming up the works. Shaving the melted bits and reassembling the switch it has worked fine ever since."
That may do it.

Any other hints out there?

Ah, gotcha. If you have the relay kit, it's a lot less likely that your switch is melted. More likely that whatever lubricant the factory used has gotten sticky. I've never had my switch apart, but it's a good bet yours is probably salvageable.

[Jacko]

Ah, gotcha. If you have the relay kit, it's a lot less likely that your switch is melted. More likely that whatever lubricant the factory used has gotten sticky. I've never had my switch apart, but it's a good bet yours is probably salvageable.

Several years ago I had the same problem. I took the switch apart and was surprised at how complex it was. I took off
a couple parts which led to removing a couple more parts. At that point I was lost. I gave up on putting it back together
and bought one from DMCH