The Stovebolt Site Forums The Shop Area The Electrical Bay Repair your headlight switch...tutorial

Earlier this morning I said these fail. Actually the same thing normally fails in every one of them. Let's see how to fix it, since this switch will be infinitely better than the imported ones.
1. An overview of your switch. This is one I removed from a truck about 40 years ago and never used because it doesn't work. (first image below)
2. Press the release button on the bottom and remove the knob rod. You may have to wiggle the knob back and forth to make this happen. (no image)
3. Using a screwdriver, carefully bend up the tabs on one side only. (second image below)
4. Remove the top and contactor and the fiberglass plate below the contactor. (third image below)
5. The top of the contactor and the three bumps. (fourth image below)
6. Remove the insides (except the sliding detent rod...leave it in place as shown). Discard all the broken bakelite bits. (fifth image below)

Please jump to next post (image limitation requires this)

Now that you've cleaned the old junk out, get some common chassis grease or cornhead grease and:

7. Begin reassembling, greasing the sliding detent rod. (image one below)
8. Be certain to grease the bottom and sliding sides of the bakelite piece. (image two below)
9. Install the bakelite piece over the sliding detent rod and then angle the greased rod clip in as shown. (image three below)
10. Install the three small springs. (image four below)
11. Set the contactor and fiberglass plate below it in place. (image five below)

And now, please follow to next post...

Continue with reassembly.

Carefully set the top plate on, sliding it into the two tabs you did not bend upward. Turn switch up so you can check to be certain the contactor is still positioned correctly. (image one below)
Press top plate down and hold in place. (image two below)
Using water pump pliers, carefully bend back the two tabs you bent outward to release the top. (image three below)
Now connect the power supply for the dash lights. (image four below)
And now you're finished and your switch should work well for a long time.

Okay, what happened to cause your switch to fail? Generally the end of the sliding bakelite piece breaks off, these pieces fall down and prevent the slider from working at all. Take a look at image five below. This is where all the plastic bits and pieces you cleaned out earlier originated. Good luck.

One further image. Please look at what you may see when you first remove the top plate. The broken bakelite pieces (broken by the knob rod pushing into them) have fallen off behind the slider and will make movement of it both erratic and finally impossible. You can see where the knob rod would strike the back side of the bakelite slider in this image. The switch (aside from this) is otherwise a very simple design.

Interesting Thread... are there parts kits available to repair these?

Never say never, but I've never seen any parts available, Rusty. You know for years these sold new for $6 or $7, and I'm sure very few people ever took one apart to rebuild it. In fact, it was widely known you could buy a brand new one from Western Auto for $4, remove the "universal" knob/rod and slip your AD knob/rod straight in there. It was the same switch, made by Delco and sold as a universal model. The only trick was you had to file a new notch for it as the lock tab was 45 degrees different. My truck has both of these notches and it originally came from California, so I'm certain some parts place out there sold the same switch. But things have changed.

From what I've seen only one part really wears out so to speak. That is the bakelite sliding block. The slot holding the knob/rod keeper wears and this lets the knob rod slide ever so further in. All it takes is one hard push of the headlight knob inward (which happens when the bakelite slider and the sliding detent pin lose lubricant) and pow...the back is knocked out. Once that happens, the switch is on borrowed time. I suppose you could rebuild the top piece with small brass screws (to replace the pins and rivets) if need be, but I've never seen one wear so far that these quit working. This switch had seen a decent amount of use when I got it, and you can see the contacts on the top plate are nowhere needing attention:

Awesome write-up Jon!

Thanks! Hope it helps. Sounds like this will fix your situation. Actually I have another of these I'll be repairing soon. Same problem...won't push in all the way and the image up there shows why. Good luck.

This should be a tech tip.

I mentioned I had another switch needing attention and I have some nice blank formatted diskettes, a cup of tea and 30 minutes to kill. This switch was sold originally by NAPA (I bought it maybe 30 or so years ago) and like the ones sold by Western Auto was made either by Delco or the subcontractor who made it for Delco. Same exact switch made using the same dies, etc. But this one wasn't acting the same way. It:
1. no longer was smooth to use
2. turned the lights on but rather erratically
3. didn't dim dash lights anymore.

So, let's look inside. I'm pretty certain we're going to find something different and have some new problems to fix, but the broken bakelite may also be a problem.
First, a look at the switch...image 1 below
Second, I bend carefully back two tabs on one side only...image 2 below
Third, I lift off the top and slide it out from the tabs I did not bend back and...Aha! The problem you can clearly see in image 3 below. At least one of the problems. As you can see, the contacts are worn and ugly looking and there's generous evidence of dust, dirt, etc. Not pretty but not a death sentence by any measure.
Four, we see the contactor is the same exact design...image four.
and Five, you can see I've spent a few minutes with a small piece of wood and some 100 grit sandpaper wrapped around it to level the contact plate and contacts back to a like-new condition. I'll go over them with 320 sandpaper and then 600 grit sandpaper to make them nice and smooth. These guys aren't going to give us any trouble for a while now.

Please move to next post...

Now, clean and sand with 320 and then 600 grit paper the contactor nubs to make them nice, smooth and shiny...image one below.
When finished, remove parts as we did with the first one...image two below. Note the bump on the rod retaining clip always faces the side with two springs. It won't work if you install it backwards.
And hey...Look Ma! No damage to the bakelite box in this one. That's nice. Image 3 below.
Using mineral spirits or general paint thinner (not lacquer thinner, though), clean the bakelite slider, the retaining piece and the inside of the box. Then as we did above, using chassis grease or other medium weight grease lubricate the detent slider, the bakelite slider, the retaining clip and reassemble carefully. See image 4 below. You can push down on the bakelite piece and move it back and forth to spread the grease and make certain you have a smooth moving mechanism now. Add more grease if needed.
Now image 5 below may be repetitive, but I want to be absolutely certain you don't install the clip backwards and have to do this all over again. The side without the bump faces the side with only 1 spring.

And please proceed to the next post...

Install the 3 springs...image one below.
Set contactor in place as we did before...image two below.
Spread a thin layer of grease on the contactor plate and the contactor...remember this had a problem with wearing down and we want to help eliminate this. Please don't worry this will affect the switch. It will still conduct just fine. Image three below.
Slide the top plate into the two tabs you did not bend back. Image four below.
And turn it up to make certain the orientation of the contactor is still correct. Image five below.

And on we go...

Push down the top with your thumb and use your water pump pliers to bend the tabs back. Please see image one below. You will first bend from the opposing corner as you see me doing.
And next you will adjust your water pump pliers and bend from top to bottom to close the tabs as you see me doing in image 2 below.
Switch is back together, but we still have one problem left. The dash light dimmer. First, using a small screwdriver carefully lift up the rotator piece as you see me doing in image 3 below.
Next, slip a piece of 320 grit sandpaper under the rotator and remove your screwdriver. You can see this in image 4 below. Rotate your knob back and forth a bit (shouldn't take more than 6 or so times) to break up any oxidation, dirt, etc.

And now this fellow is finished and this one feels just like brand new...image 5 below. Hope this is helpful

Ok, i will try this again. I hope I'm not double posting.Our cable tel/comp. is not good. Here is an electrical layman's approach; #1 apply a good amount of Kroil Oil to switch (where ever it soaks in). this old switch has been around for probably more than 70 years. (overstock factory item), Make sure it gets into spade rod and around spring loaded push down spade release. found on flat side not connector screw side. #2 let Kroil Oil set for 30 to 120 minutes. #3 push down spade release and pull back and forth. It will release, if not have patience and try a few hours later. #4 blow out all oil with dry O2 or a filtered compressor. #5 spray in Detox #5 (about $19.00 for 5 oz.). don't spray to much, about 4 squrts. #6 dont have to spray O2 because Detox #5 is a neutral cleaner. That's about it. If you don't have any luck repeat one more time. Also pay attention to break light switch if you still have problems it will not normally draw down battery unless you have a very positive short. Jon G is obviously an expert. My system works from the amateurs point of view. In actuality my method takes more time. Doc.

Jon I'm copying your info. Wonderful information. Doc

Thanks Doc, hope it is helpful. One comment...it is just me, but I don't like to get anywhere near some things with Kroil, PB Blaster, WD40 or any other products like these (and there are scads of them out there). They spread (migrate) like crazy...it is after all what they were designed to do...and I've seen too many dashboards, speedometers, gauges, radios, clocks and many other things turn out looking like they'd spent a week inside a popcorn popper not to say something. Even a wee bit can make a mess and some of those products will dissolve paint and others aren't safe to be used on plastic. About 30 years ago I watched a fellow "repair" the sticking tachometer on a pristine Triumph Bonneville. One drop dribbled out and landed on the fuel tank and before he could get his handkerchief out, the pretty original paint was never to be the same. It is why I mentioned chassis grease. The stuff I use (called red & sticky) has a drop point of something over 500 F.

Here is another tip I should have mentioned but forgot: Occasionally the release button just won't let the knob/rod go. This is common when the slider gets completely stuck and it is my opinion when that happens it causes the retaining piece to seize in the slot. Here's a possible fix: Disconnect battery. Pull switch all the way out as if turning on the headlights. Carefully unscrew the retaining nut, pull back on the switch enough to disengage the retaining tab from the dash and rotate the switch 180 degrees. Tap what is normally the bottom of the switch (it will be facing the top now) with the handle of a screwdriver a couple of times. This is to release any broken bakelite pieces keeping the slider from being pushed back in. Please see image below. Now disconnect the wires, marking where each goes and reach around to the top and push the release button. Your rod ought to slide right out.

A friend (via email) asked if there was some way to make a headlight switch last longer. There is...put the headlights on one heavy duty relay and the tail, dash, running lights on another relay. This will keep the high amperage away from the switch and that's what stresses it. If you look at the contactor plate in the 2nd switch I repaired, amperage and use were the two culprits. If that switch had only been switching a typical Bosch type relay it never would have suffered that damage.

WOW! good to know. I worked as a gunsmith in collage and the old guy smith told me to never use WD-40 on anything especially in a gun. Under even mild heat it will crystalize and cause not only major jamming and pitting. That was in 1973. I made sure I rinsed out the Kroil oil with 90% ethyl alcohol and dried with canned air. I have copied all your advice and found a 1954 headlight switch. Can't wait to get started on it in the shop using your fantastic advice. Thank you. Is the red grease the best to use, sparingly like a very light film? Doc.

Jon, just got it apart the Bake Lite is broken. I discovered Pega Tanke'. It come in clear, black and white. I have two part mix for 60 years. This product is the best I have ever used. What do you think of spreading a thin film on the Bake Lite. I also have access to a 3-D printer. Doc.

The slider will work fine without the rear (or front depending on your point of view) bakelite piece, Doc. What happens (I think) is the slot in the bakelite wears a bit over the years allowing the knob rod to slide a bit further in when the lights are turned off. Then when the switch starts being harder to pull out and push back in (lack of lubrication, age, wear, whatever) somebody pushes the switch in a little too hard and pow...out goes the end of the bakelite slider piece. The tip end of the rod is sharp and there's only a few thousands of clearance when the switch is new. At the point the bakelite pieces get knocked off, the switch is on borrowed time because no longer can it slide all the way in and the switch can not be predictably turned off until that is fixed. But if you notice on the first switch I repaired, the end of the slider was gone, and that one is working fine. In fact, I'm using it in my truck. A 3-D printer would be neat, but that's way down on my list.

Jon
I was just messing with the headlight switch from my '51. It's different than the ones you've been working on, in that the slider is a metal box, no bakelite, and the rod doesn't release from the switch at all, but the knob screws off and has a setscrew. Maybe it's an early replacement style. I got a 12V repop for cheap and it's the same, except has a 20A circuit breaker instead of the 30A one on the original switch. Also the pot for the dash lights has a different resistance. What I was able to do was disassemble both switches and swap the pot (the slider on the 6V switch was broken off and making the rod bind up) and the circuit breaker. I now have a serviceable 6V switch to use. Here's a pic of the parts I have leftover after converting the 12V repop switch to 6V.

Kevin, thanks very much for this! I've seen one of these in the past, but I don't know who made it. And I have a copy of it which I believe was made in Taiwan (which I've not disassembled yet). I'm impressed you were able to swap the pot for the dash lights. I noticed the resistance of that coil was different on the one I have. I'm away for a bit but will check the circuit breaker when I get back.

Jon
The 30A circuit breaker on the switch I took off the truck was a Made in USA Litelfuse. The switch body had Made in USA stamped in two places, bottom under where the pot mounts and on the front (normally covered by the circuit breaker.)
The 12V switch has no markings on it except for 20A on the circuit breaker and 12V stamped on the bottom of the switch body.
Maybe I should have swapped out the switch body as well, to keep the Made in USA markings.

Both look just like Jim Carter's 1936 -1955 Headlight Switch 6 Volt Close to Original Chevrolet and GMC Pickup Truck Item # EL149

I know, I know, but I have to brag on Jon. he saved me time and money on my 54. I didn't even have to take it loose. Had plenty of room with it hanging under the dash. Works like new. Again, Thanks Jon. Ed

JonG Long ago on one of my first trucks the switch got stiff so I took out the knob slid a WD 40 tube way in there discharged it and pulled out spraying. Switch worked fine after that,do you see any problem doing that ??

No, I don't. As long as the bakelite in there hasn't broken, that is. As I mentioned, this happens sometimes and when it does, those chips fall down and stop the slider from making full travel. As long as it is working, all should be ok. Taking them apart and cleaning/restoring as I've shown makes them just like new again, however.

Jon,
You have seen my shop so when I say something is lost it is not only possible but probable. With this said I have a quart jar of bakelite replacements that a circuit board place in Addison made for me 40 (or more) years ago. Done as a favor by the shop foreman in exchange for ignition work on his 37 Ford. All this rambling to say you might check with somewhere for a replacement part being made. Reality is they would probably want an order for a thousand pieces. If I find the jar which is now about half full, it's yours.

Thanks Evan,
I did look for replacement parts several months ago but couldn't find any. And I of all people understand about things being misplaced. If you happen to run across this, I'll be very happy to drive out and get it, but please don't go on a hunt for it.

I'm bumping this to the top to make it easier for one gentleman to find it...

Thanks this worked out great my switch was stiff and I had to wiggle it to get the lights to go on sometimes ,turned out the contacts were dirty and all the grease was dried up and making it stiff . I also refurbished a spare they both had no broken pieces so I am in good shape .

Speaking of repairing your headlight switch, has anyone found a good solution to the instrument light dimmer function in the switch? I've clean some of these dimmers up and they work okay; however, I came across one that doesn't have any continuity in the dimmer. It seems that a lot of these switches get the 'wiggle' treatment that KEVINSKI mentioned to get them to illuminate.

Hey Jon G, can you come up with some new component to retrofit these switches with to solve the dimmer functionality? The dimmer is staked into the switch bracket, but they can be removed with a little filing. A potentiometer comes to mind. How could we modify one to nest in the headlight switch bracket to improve its operation?

BTW, Jon's tutorial is excellent for reconditioning the headlight/parking light functionality. It should be a Tech Tip!

Andy, I was able to put a dimmer from a 12V aftermarket(?) headlight switch in my original. See my post at the top of page 3 of this thread. It's a different style switch than what Jon is working on.

Thanks Kevin, that certainly looks doable! I'll have to see if I can get my hands on one of those 12V aftermarket switches.

Thanks again,

That style may be available in 6V as well. I used the 12V one because I had it on hand.
Yep, here's the same style in 6V: Headlight switch

How do those aftermarket switches work, do they hold up for the long haul, or are they like most aftermarket reproduction items? Just wondering.......

Thanks Andy,
Once upon a time the Tech Tips were going to be updated/etc, but I haven't heard anything about that in a while so I assume it has been shelved. You can scab in a dimmer from another switch or you could repair the one in the faulty dimmer you have. This is a simple wire-wound variable resistor. The key is the imported copies of this switch have different resistance values in some cases and that means they'll work a bit differently. Bottom line you won't get the same range of dim to bright. I've actually been thinking about wire-wound resistors lately. Once upon a time the best 12 to 6 volt adapter was made by a company in California (Columbia Radio). I've been thinking about the possibility of making those again. Same exact principle but no need for variability.

They seem pretty durable. The only reason I messed with mine is the post that the dimmer pot runs on had broken off. Otherwise, it worked fine.

Speaking of the dimmer ,I found another switch only this one the spring for the dimmer keeps popping out what holds it in and is it only attached on the one end .I was thinking of a few dabs of epoxy on the bottom side

That coil is what is known as resistance wire. It is the same thing (basically) that is used in hair dryers, heaters...things like that and in some cases this wire is used in certain styles of rheostats. When current flows through these types of wire, they resist that current much more than normal wire does. This makes the wire get hot and that's why it is encased in ceramic. The ceramic housing keeps the wire from heating other things to the point of danger. So, to answer your question about epoxy, the correct response is: maybe and maybe not. It all depends on how hot the coil gets and how tolerant of heat your epoxy is. Maybe you folks recall when I was working on the fuel gauge sending units. Actually I still am, but that story is a slowly developing one. The same wire is used and the reason it presents no danger in the fuel tank is that only a tiny bit of electricity is fed through it. In the headlight switch, more electricity is fed through and that's why the electrical engineers (and the people in other countries who have copied these switches) use a non-combustible material to hold those coils. The wiper which wipes across the coil connects different points of the coil and that's what makes the bulbs dim or bright...the different points of resistance or lack thereof. If I were to use epoxy, I'd use the original JB Weld. It can withstand 500 degrees F on a fairly constant basis and 600 degrees F for very brief exposures. Good luck.

Thanks will give it a try with the j b weld as it seems when the wiper goes over it it pops outs and jambs up .