VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Headlight Switch Problem 1947 Convertible

I have a 1947 Chevy Cabriolet and when I am driving with headlights on the back of the headlight switch is getting that hot it is melting the soldier out of the fuse. It was a NOS switch. Any ideas why?foruph@comcast.net

Yes, you have a short in your eletrical system.

Any suggestions on how to check out where?

NO because with 60 year old wiring it could be most any place. You could try disconnecting one wire at a time from the head light switch (like the tail light wire, head light wire) and see if it dosen't heat up with one of the wires disconnected. Then if you can pin-point the area check the wiring to that "department" for loss of insulation, etc. I probably would check the wire from the headlight switch to the dimmer switch first, then the wires to each head light, right up to the sealed beam.Also look at the tail light wires in the trunk and at the back of the tail lights, or the dimmer switch its self.

I have replaced all wiring about 8-10 years ago. I did put turn signals on it about 2 or 3 years ago. I used the Guide 6001 with new wiring also. I could have a pinched wire somewhere. I tried the halogen bulbs and that was a mistake. I haven't had time to hunt yet but should be interesting. Thanks

I tried the halogen bulbs in my '50 also. Your correct about being a mistake.

I am curious, what didn't you like about the halogen headlights? I stuck w/ the standard just to keep the system original, but wondered about those halogen systems. Seems like they should offer a brighter whiter light.

They pull way to much current for the old 6 volt system. One gentlemen told me he had them in and was sitting at a red light with his turn signal on and the smoke started to roll out of his switch.

I was refering to the halogen tail light bulbs. They were only slightly brighter and they caused such a heavy eletrical draw the the directional switch on my '50 would overheat and smoke if the brakes lights were on for any length of time....such as in heavy traffic. The brakes light wiring goes thru the Guide factory dir. switch.
If your head lights are yellow you have poor grounds.
I do use halogen sealed eams in my 12 volt cars.

I would like to try a headlight relay. I am curious to know if any one out there may have a 6 volt preferable a 5 prong but would settle for a three and I would like to have it fused. Old Echlin Ignition numbers are HR 300 (5 prong) & HR 300 And Standard Ignition # of LR 33 or LR 31. The 5 prong will take care of both high & low beam.

When I was driving my '39 regularly to work in all kinds of weather, I used a double headlight relay to avoid blowing the 30 amp fuse on the headlight switch. The car had sealbeams and the fuse would blow occasionally at the worst times. It got very hot when the lights were on, so I installed a double relay which was fused and that solved the problem. After that, The fuse on the switch was cool to the touch and never blew again. The '48s have a circuit breaker type switch which might solve your problem if you're blowing fuses. It resets itself when it cools...I use halogen tail light bulbs in my '48 and they do draw a lot of current, but I don't drive it at night much..

Thanks for the info. I am working on getting the 5 post relay so I can take care of both high & low beam. I think it will cure my problem from what I am leaning. This is a great place to get help.