VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1936 Chevrolet headlight switch resistor

Yes, I was wondering if anyone knew about the resistor on the back of the headlight switch? I checked mine and it is burned out, one of the wire wraps is burned. I have been having a problem with the charging system not charging. I found that the field wire that runs back to the headlight switch was connnected to the "GEN" side of the cutout switch. I'm having the generator checked and I was wondering if I needed to replace the headlight resistor and where I could find one? Any help would be welcomed!
Thanks,
oldndragon 1936 Master coupe

I just purchased one a little while back. The only place I found a NOS headlight switch was at www.yesteryearantiqueautoparts.com
It cost about $150.00 plus shipping. It came in original cardboard box #485-z Delco Remy. I had the same exact problem you are having. After installing the new switch it solved all the charging problems, It works great. I think he said that he only has a few left. He is out of Florida, You can either call him or E-mail him, but check his web page out he has alot to offer, and a really nice person that takes his time to help you out. Tell him Ken from St.John Indiana sent you to him.

You could possibly purchase a new resistor from an eletronics store. It be be 1 ohm restance. You could find an old 1934-37 Master light switch and remove the resistor.The resistor could be by passed as it would be on a Standard. You could purchase the new 1934 Master switch that I have and remove and use just the resistor.....(for a lot less than $150.00).

Oldndragon,
Just thought I could help you out. For me It was just easier to get the part and swap it out.

Thank you all for your responses. I guess my question is what purpose does the resistor serve? Im only guessing that the item I am looking at is the resistor. Or is it a fuse? It is a small fiber board with spaced wire wrapping secured with two small screws on each end. Its located on the right side of the light switch. From what I understand now, I dont really need it. I had my generator rebuilt and installed a new cutout but I dont want to install it until I understand the switches relationship to the gererating system because of the field wire to the switch. What do you think? Thanks to Cheif and Gene for your help.
Oldndragon

The fields in the Standard generator are grounded to the generator case. The Master fields are grounded to the light switch. (fields must be grounded for generator to charge).
From Chevrolet Mechanic's Repair Manual......
The resistance unit is mounted on the back of the light switch and is connected in series with the (generatr) field windings as shown(in picture).When the light switch is turned on , the resistance unit shorted out of the generator field circuit by a common ground, thus automatically raising the charging rate to take care of the added load. When the lights are turned off the resistance unit is again connected to the fiels circuit which automatically reduces the charging rate.

In other words the reistor decreases the charging rate. To increase the charging rate when lights are not on pulling out the switch half way betwween the off and parking light position will increase the charging rate. If the wiring was hooked up eleminating the reisitor the gen. would charge at the higher rate at all times. I think I explained this correctly.I would do this for a temporary fix and still would hunt down a resistor or switch.

Hi Gene, So how would I hook up my generator in the meantime? Should I leave the field wire off the generator until I find a new switch or hook it up? I do not drive the car at night anyway so I dont need headlights but I have found a place in Portland Oregon that has alot of Chevrolet only NOS parts called "Old Car Parts". He says if we can match switches $50.00 for NOS. By the way, how much for your resistor?
oldndragon

Just ground the "Field" wire on the Field terminal of the generator to the generator case as a temporary fix and you are set to go until you replace the resistor.

:) :grin:

Thanks Dog, thats just what I did and its charging great! I also picked up a 1 ohm resistor at Radio Shack I will install that on the light switch and see how that works until I can find an original replacement.
Thanks to you all for the help! I sure I'll talk to you again!
Oldndragon
1936 FA Master coupe

No problem! All of us here are glad to help you out.

:) :grin:

Two values for the resistor were available:0.75 ohms or 1.05 ohms,depending on the use of the vehicle,plus whether it was a commercial or a Master 6.

Thanks for that information. I purchased a 1 ohm resister at Radio Shack and install it on my light switch, It works fine. When I pull the light switch part way the charging rate goes up. I understand that that is just what it should do. Anyway thanks for the information.
oldndragon
1936 FA Master coupe

In the US there were three different resistors. The production resistor was 1 ohm, There was a 3/4 amp for "extra" charging and a 1 1/2 ohm for conditions where the battery would be over charged......such as an owner that would have done extensive day time country driving.