The Stovebolt Site Forums The Shop Area The Electrical Bay Dimmer Switch Issue

Hello all,

I am having an issue with my dimmer switch, on my stock, 6 volt, 53 3100. Low beams work fine. High beams, not so much. I have checked the wiring. Everything is wired correctly. Using a volt meter, I tested the terminals on the dimmer switch. Getting power to both the low beam terminal, when the dimmer switch in on low and power to the high beam terminal, when the switch is on high beam. The high beam indicator light on the top of the speedometer illuminates as it should, for high beams. Unless I am not thinking of something else, I am guessing my NOS dimmer switch is the issue. Has anybody had any experience or luck fixing one? If so, what is the best and most efficient way of fixing one?

As always, thank you in advance for your sharing your time and knowledge.

Rugo

Dimmer switch contacts can get corroded and still show voltage, but lack the ability to carry enough current to burn the headlights bright enough. Try spraying contact cleaner into the switch contacts and cycling it several times. I'd recommend using a couple of Bosch-type relays to power the lights, and use the dimmer switch to trigger the relays. You can run a large diameter wire to the radiator core support area and place the relays close to the headlights so they get full battery voltage without having to run the circuit all the way to the cab and then to the lights.
Jerry

Thanks Jerry. I will give that a go.
Rugo

I had the same issue. Dims worked, brights didn't, but the indicator did. The only time the brights worked was when I pulled it in the garage to track down the problem. Frustrating! I replaced the dimmer switch with an NOS switch, but that didn't help.

I discovered that the high beam terminal on the headlight switch was loose in the switch body. I replaced the switch with one of my three spare headlight switches. Two of my spares had bad high beam terminals. One was burned right out of the switch.

Check and/or replace your headlight switch and then, as Jerry suggests, run relays. That will prevent the the headlight current from running through the headlight switch.

You said " I am guessing my NOS dimmer switch is the issue." Did you just recently change out the switch? I just had the same issue and corrected it yesterday. My original switch went bad. I ordered a replacement. I was careful to move the wires from the old switch to the same location on the new switch. Problem was that the new switch had two of the terminals in a different location than the old switch. Everything appeared to be correct. I tested with my volt meter and would get voltage at a different terminal when I click the dimmer but my low beams did not work. I discover the change in location of the terminals. Old switch had the battery terminal in the top position. New switch had it in the middle. I switched the two wires and the headlights worked properly.

Rugo, with the differing opinions let me add another. If it was me having the issue I would first put the dimmer in the low beam position, access the dimmer switch, remove the high beam wire(s) then temporarily contact them to the low beam side of the dimmer switch. If the high beams come on it's the dimmer switch. If not, your journey isn't over. My personal experience is 90% + of the time it's the dimmer switch. When mine started going bad in the '38 I did as Jerry recommends and got a few more months out of it but eventually had to replace it. The dimmer switch lives in a bad place for an electrical component so I'm surprised they don't fail more often.

Thank you guys for all of your help with fixes for my dimmer switch issue. This is a little embarrassing to admit. Until just the last week, I have driven my truck very sparingly, I had very basic insurance on it. So, mostly just around the neighborhood. I finally felt as though it was time to take it out for more city driving. I got it insured properly and headed out. As happens when you are driving a truck that had every nut, bolt, and part removed and replaced, things don't always go as planned. No matter how careful and thorough. you think you are. After taking a long look at everything, I discovered that the high beam wire to my drivers side fender junction block had worked its way loose. Obviously, I didn't get it screwed down as well as I thought. After driving over some bumps, it must have worked loose. After reattaching it, both high and low beams work great. It was a good lesson learned. I am very grateful for all of your input and help. If I ever develop the same issue, and all my wires are in place, I will know how to fix it, because of the help and support that my fellow bolters have given me.

Thank you again for all of your time and efforts.

Rugo

Glad you found the problem! I've had similar things happen to me, so don't feel bad. We're all glad when it turns out to be a simple fix!!!

At least it was a headlight and not a u-joint or a connecting rod bearing!