1941 Plymouth Headlight Switch

[oilslickwillie]

Drove home yesterday and now my headlights, tail lights, brake lights, interior, all, do not work on my 1941 Plymouth Coupe. I pulled the headlight switch knob on and off several times and occasionally the park lights would come on, no headlights. Then later doing this none of the lights would work. I pulled the fuse located in the headlight switch to check it and it looked okay. I did notice that a very small piece of aluminum looking piece was inside the fuse holder. Don't know where that came from or why it was there, unless previous owner used it to make a fuse longer???? Does anyone have any ideas what could be wrong. I tried to remove the switch but don't know how the headlight knob comes out of the switch. Other old cars I have owned had a button on bottom to remove the shaft but can't find one on this switch. Can someone inform me how this shaft comes out before I can remove the bezel? Thanks.

[desoto1939]

I have a 39 Desoto so this is how I remove the knobs on my switches.

Look under the knob there might be a slot about 1/8 wide. If you look up inthe slot there is a flat spring clip that put pressure on the shaft that comes out from the switch.

Take a small screwdrive like a glasses screwdriver that you use to tightn the small screw on your glasses. Put the blade against the flat metal spring and put pressure on the spring by moving the spring forward this then loosend the pressure on the shaft and you can pullthe knob off the shaft.

There might be a set screw on your knobs not sure. But this might help.

Rich HArtung

desoto1939@aol.com

[Plymouthy Adams]

move/detent the spring just enough to loosen its grip on the shaft..these are spring steel and quite easy to snap the retainer..once that is done well..it's all over just about as the headlight knob is a bit hard to place your hands on new..

[oilslickwillie]

Thanks for the info. I did get the switch out of the dash as suggested. Cleaned the contacts and bought a new 30 amp fuse that was just about 1/16" longer. Got the lights to work all except the headlights. Finally figured out that the brights work, but not the low beam. I guess it may be a bad dimmer switch on the floor. I don't think the headlight switch cares if the headlights are high or low beam so thats why I think its now the dimmer switch. Everything works, just have to drive with the brights on. If I dim my lights, they go off, thats not good. Will have to try and locate a dimmer switch next I guess.

[oilslickwillie]

1941 Plymouth Coupe. After reading several posts on here about dimmer switches, I tried what others had recommended of pressing the dimmer switch on and off several times. Doing that made both my high beam and low beam lights work as they should. Thought I had the problem licked but found out that where the fuse goes in the headlight switch, got so hot you could not touch it. Now don't know where to look to fix that problem. Any suggestions on what to check next. All the lights work now, just the fuse holder gets to hot to touch.

Edited October 17, 2012 by oilslickwillie

[1941coupe]

I would replace the dimmer switch, or at the very least remove all four wires going to it and clean the sockets with a small, round, wire brush. Blow out with compressed air and reconnect your wires. Also, clean the bullets with a solvent/contact cleaner. And, check your headlight grounds. They are located inside your headlight buckets. It's just a sheetmetal screw with a terminal.

[oilslickwillie]

Thanks 41 Coupe. I will give that a try tomorrow and will post what happens. What if I bypass the dimmer altogether, if the fuse does not get hot that would tell me if the dimmer is bad, right?

Jon

[oilslickwillie]

I got up early today and did some more troubleshooting. I grounded the headlight switch, pressed the brake pedal and the fuse holder only got a little warm. Not a brake wiring problem! Next, I pulled the light switch to park and held on to the fuse holder and it got a little warmer but I could still hold on to it without burning myself. Next, I put the light switch to headlights on low beam and the fuse holder stayed warm but I could still hold on to it. Pressed the dimmer switch to high beam and within 3 seconds the fuse holder was so hot I had to let it go. My guess it’s the dimmer switch or ground on the headlights. Do you think I may be on to something. I will clean the connections today and see what happens. Do any of you think I'm on the right path on this problem? Thanks.

[oilslickwillie]

Took the light switch out and clean the entire thing, contacts, wiring, connectors, fuse holder in and out and the fuse holder still heats up with the headlights on. Don't know what to try next. Need to give it a couple days before I go crazy trying to figure this out. The grounds look okay also. ???

[Plymouthy Adams]

let the switch power up a relay..takes all current off the switch...only one relay needed if you interrupt the power between the light switch and the dimmer switch...

[oilslickwillie]

Tim, that makes sense. Do you have a wiring diagram for me to do this. Not sure which wire on the headlight switch to use. Only reason I say this is I thought there were more than one power wire coming off the switch (i.e. tail lights, headlights, etc.) This is a light switch on a 1941 Plymouth Coupe.

Edited October 18, 2012 by oilslickwillie

[Plymouthy Adams]

the power feed you want to go to the relay coil to energize when lights switch is pulled on is the terminal marked H on your headlight switch....

[oilslickwillie]

Tim, thanks. Today I took your advise and checked it out further. I pulled the wire marked H on the light switch and of course the headlights would not work so I was sure I had the right wire. If I understand you, the relay should go between the H and the dimmer switch. Do I need to have a wire from the battery or the hot side anywhere in this wiring. The relay I purchased is 6 volt and has 3 contact points on it. Also, the previous owner of the 41 Plymouth re-wired under the hood on the contact where the wiring goes to the headlights and I think he used to small a gauge wire, that probably contributed to the hot fuse isse. I hope this relay idea works. Thanks, Jon

[Plymouthy Adams]

the headling wire H you can cut and supply this as the power wire to energize your relay with the other side of the relay coil going to ground. Suggest a trip to the parts house and get a Bosch style square relay rated 30 amp or better and get the one with the associated wiring pigtail..the insturcion as to the which wire is hot, ground, supply and line will be included..the other side of the H wire going to the dimmer is the LINE connection of course SUPPLY is a direct feed wire (fuse/breaker inline) from the battery and the last wire is coild ground which goes to ground..the coil connections are not concerned on polarity...

http://images.search.yahoo.com/images/view?back=http%3A%2F%2Fsearch.yahoo.com%2Fsearch%3Fei%3DUTF-8%26p%3Dbosch%2Brelay%2Bwiring&w=160&h=121&imgurl=www.bing.com%2Fimages%2Fsearch%3Fq%3Dbosch%2Brelay%2Bwiring%26id%3D72DBD29AC634EAA15BE5D3584855F1F33A42987B&size=&name=search&rcurl=http%3A%2F%2Fwww.bing.com%2Fimages%2Fsearch%3Fq%3Dbosch%2Brelay%2Bwiring%26id%3D72DBD29AC634EAA15BE5D3584855F1F33A42987B&rurl=http%3A%2F%2Fwww.bing.com%2Fimages%2Fsearch%3Fq%3Dbosch%2Brelay%2Bwiring%26id%3D72DBD29AC634EAA15BE5D3584855F1F33A42987B&p=bosch+relay+wiring&type=&no=2&tt=115&oid=http%3A%2F%2Fts3.mm.bing.net%2Fth%3Fid%3DH.4519088058140178%26pid%3D15.1&tit=...+.net+-+View+Single+Post+-+Should+I+get+updated+fuel+pump+relay&sigr=1324tmb10&sigi=12rmen86l&sigb=11shsdbs7&fr=yfp-t-701

heck of a link but this is what you need to know...87A is not used for this set up as it NC connection of the switched contacts and you need only the NO contacts..

now, if you are still 6 volt..you got to find the relay you want to use...solid state one are inexpensive and are hermatically sealed so mounting and polarity is not a concern and are multi voltage friendly 3-32 volts on the average is their operation range to energize..

http://www.ebay.com/itm/New-Solid-State-Relay-SSR-40DA-40A-250V-W-I-O-3-32VDC-24-380VAC-/230865728006?pt=LH_DefaultDomain_0&hash=item35c0ab7206

outside of wiring it for you myself..this is all you need to accomplish the job..

Edited October 19, 2012 by Tim Adams

[1941Rick]

Comment.....heat is the result of current draw.

Question......what is the current draw and what size fuse do you have?

[oilslickwillie]

30 amp fuse. I did discover the previous owner used a small gauge wire to the headlights, that may be part of the problem. I am going to try and wire in a relay to the headlights and that should bypass the fuse and I will wire an inline fuse to the headlights itself.

[1941coupe]

I would get to the root of the problem instead of trying to add a relay as a band-aid fix..this was never part of the original designed-in electrical system. Adding a relay is not necessary and needlessly complicates an already simple system. I would try to keep you cars electrical system as original as possible, there are 7 wires that connect to your switch. An original wiring diagram can help if you don't already have one, you will be better off in the long run.

[Plymouthy Adams]

the replacement of a stock headlight switch that may have loose internal contacts and drawing extra current..but if its a heat problem due to the added current..a relay will prolong the life of the original switch without any real modifications to the wiring harness..

[1941coupe]

the replacement of a stock headlight switch that may have loose internal contacts and drawing extra current..but if its a heat problem due to the added current..a relay will prolong the life of the original switch without any real modifications to the wiring harness..

Ahh, in that case it's time for a replacement switch. I just bought a correct n.o.s. one with built-in 30 amp fuse at an auto swap-meet for $5. I am in the process of installing a new harness in my 41, and undoing the mess the previous owner did/added.

[Plymouthy Adams]

for those that are fortunate to have a replacement and or carry a spare that is fine but until one lucks upon a replacement and still wishes to drive their car until they get lucky so to speak..this is a very workable get by that will do no harm and can be retrofitted back to stock in a blink of an eye..

each owner will have to make the call on stock or mod and whether to change for a temp while looking for a replacement part of go mod and stay..it was just a suggestion...

[1941coupe]

I agree with the getting lucky part, I was there for no more than 15 minutes when I found it, talk about lucky. I'm the type that does not mind if the car sits for a few weeks while the correct part can be found. As long as I can start the engine at least weekly I don't mind, I'm not in a hurry but with others it may be different, especially if it's their only car. Most people who own these cars have others they can use to do any parts chasing with.

[oilslickwillie]

I figure the relay will take the heat off the fuse since it is basically bypassing the switch. I agree, a new NOS switch would be fine but I have been having a hard time finding one unless I want to give $65.00 plus shipping. As for being original, that does not bother me since the 41 coupe has a 53 Dodge engine in it already. I just want to drive it. I basically built streetrod and they are easier to work on and the parts are simple to find.

[oilslickwillie]

Tim, thanks for your help on the relay for my headlights. I wired it in with an inline fuse and it works great, no heat at the switch fuse at all. Of course, when I finished wiring it and tried it the first time, both the headlights and park lights came on at the park light switch knob. I knew that was not right and also the switch became very hard to pull out. So, I pulled the light switch, took it completely apart, shined up all the contacts, white greased the switch slide box inside the switch, put the four springs and contact plate back in and it works great. Now everything is working as it should. Two of the small contact springs somehow got pulled out of their bases and that was shorting the switch. It may have just been the dirty switch from the beginning. At least no heat at the light switch fuse at all. The light switch is easy to open and repair so I should have tried that first but I like the relay idea even more. Again, thanks Tim.

Jon

[1941coupe]

Well gentlemen, now I am having this same perplexing problem. I have rewired the entire car as it was originally. Everything has worked great for a couple of months. I was driving home at night last week and I lost the lights. I found a blown fuse and replaced it with another 30 amp. My switch is a replacement n.o.s. switch, it did not come packaged but looked and operated as brand-new. When I pull the switch out to the first detent, the built in fuse holder gets too hot to touch within 15 seconds or so. I did not know these  switches were repairable since they are put together with crimped over tabs and I would be concerned that they would break upon reassembly. I will remove the switch and try to disassemble it. I operates perfectly mechanically, but perhaps the contacts inside are dirty? Has anyone come across this problem before? Any further help would be great.

Edited February 7, 2013 by 1941coupe

[TodFitch]

I don't know how your switch and fuse holder are assembled, but on my car the fuse holder was riveted and over the years that had oxidized and become a bad connection. The result was that it got hot enough to melt the solder in the end caps of the fuse. Of course this would only happen when you had the lights on as they are the biggest power draw on the car.

 

Fix was to clean up the riveted connection really well and then solder it to provide a permanent low resistance connection. Car was 44 years old when I did that fix and its been 36 years since with no further issue.

 

As I noted, I don't know how your switch and fuse holder are assembled, but you might want to inspect it to see if that might be a problem.