DB26 Posted December 7, 2019 Share Posted December 7, 2019 Hello everyone, Is there a modern coil or resistor used to replace the dimming coil used on Clum headlight switches? I have a 1926 Dodge Brothers with the 6 volt 2 unit system. Like the coil seen in this photo: Photo courtesy of R.White Link to comment Share on other sites More sharing options...
Mikefit Posted December 8, 2019 Share Posted December 8, 2019 I may have the dimming coil ur looking for. Mike Link to comment Share on other sites More sharing options...
DB26 Posted December 8, 2019 Author Share Posted December 8, 2019 9 hours ago, Mikefit said: I may have the dimming coil ur looking for. Mike Thank you. I will send you a private message. Link to comment Share on other sites More sharing options...
Mikefit Posted December 10, 2019 Share Posted December 10, 2019 I found thedimming coil it looks somewhat smaller the the one you show but it is coiled from both ends and has I would say some kind of asbestos wrapping and hard to see metal eye lets on both ends. Mike. Link to comment Share on other sites More sharing options...
platt-deutsch Posted December 10, 2019 Share Posted December 10, 2019 i have replaced them with a 25 watt wire wound resistor. I may have the specs in my shop someplace. Link to comment Share on other sites More sharing options...
DB26 Posted December 10, 2019 Author Share Posted December 10, 2019 Thanks guys. I think a modern wire wound resistor would probably be better. If you have the specs, I would love to hear them. Link to comment Share on other sites More sharing options...
TonyAus Posted December 10, 2019 Share Posted December 10, 2019 Check the impedance (resistance) of the old coil with a multimeter . I have a vague recollection that it should be in the area of one ohm. Link to comment Share on other sites More sharing options...
DB26 Posted December 10, 2019 Author Share Posted December 10, 2019 1 hour ago, TonyAus said: Check the impedance (resistance) of the old coil with a multimeter . I have a vague recollection that it should be in the area of one ohm. I will check. Do you know what disadvantages there are to using the original? I only assume it wouldn’t be a good idea since it’s essentially just a coil of wire that I assume could cause a fire. Link to comment Share on other sites More sharing options...
nearchoclatetown Posted December 10, 2019 Share Posted December 10, 2019 No disadvantage. It is nichrome wire, an alloy that gets hot and causes a resistance. They were used for years and are not a problem. You could probably measure the diameter and length and make a new one if you have to. Your electric stove element is built the same way. 1 Link to comment Share on other sites More sharing options...
DB26 Posted December 14, 2019 Author Share Posted December 14, 2019 I tried measuring the resistance of my old coil and my readings were strange. The number kept jumping around depending on where I took the measurement on the ring terminals. I was getting .80 kOhms, 100 kOHms and .1 kOhms at different times. I probably need to clean the terminals really well. I went ahead and tested the coil in a circuit using my battery eliminator. I had the coil in series with a 6 volt bulb. It dimmed it down pretty far, just had a warm glow. And boy did it get hot. By the way, is that asbestos covering the wire? It sure reminds me of asbestos. Link to comment Share on other sites More sharing options...
nearchoclatetown Posted December 14, 2019 Share Posted December 14, 2019 DB26, I think you are thinking too much. DB headlights were only 32 candlepower. Does it really matter if the low beam is 26 or 16? Link to comment Share on other sites More sharing options...
DB26 Posted December 14, 2019 Author Share Posted December 14, 2019 17 minutes ago, nearchoclatetown said: DB26, I think you are thinking too much. DB headlights were only 32 candlepower. Does it really matter if the low beam is 26 or 16? You have a point. But any comments on the asbestos and it getting really hot? Link to comment Share on other sites More sharing options...
Bloo Posted December 14, 2019 Share Posted December 14, 2019 (edited) It is going to get hot. I don't see any asbestos, I wouldn't want any today either. A resistance of the original value will dissipate the same amount of heat when used with the same bulbs, period. You could use a modern resistor, Something much larger would reduce the surface temperature, even though the total amount of heat released would be the same. Then you would probably have to support the resistor, and do so with something that would not catch fire. I just looked again and I still don't see asbestos. If this were a tube around the outside of the coil, perhaps you could use some of the fiberglass woven tubing used as high temperature insulation in appliances. If the bulbs were of a different candlepower (that would imply a different wattage), the resistance of the coil would have to change also to get similar dimming results. Assuming this resistor dims both bulbs, you need the correct wattage bulbs, both in the circuit, wired as they are in the car, for any sort of meaningful test. Edited December 14, 2019 by Bloo (see edit history) Link to comment Share on other sites More sharing options...
nearchoclatetown Posted December 14, 2019 Share Posted December 14, 2019 I am not positive what you are trying to achieve here, but try this. Take a ballast resistor and hook it to your switch. A ballast resistor was used by Chrysler Products well into the 70's to lower voltage to the ignition points. Should be easy to find even new if you have to. It has a bracket to hold it, and porcelain to insulate it, but ti's still going to get hot. 1 Link to comment Share on other sites More sharing options...
Machinist_Bill Posted December 14, 2019 Share Posted December 14, 2019 8 hours ago, nearchoclatetown said: DB26, I think you are thinking too much. DB headlights were only 32 candlepower. Does it really matter if the low beam is 26 or 16? Just a correction. They were 21 CP. 1 Link to comment Share on other sites More sharing options...
jan arnett (2) Posted December 14, 2019 Share Posted December 14, 2019 I find with old cars you need the maximum illumination and usually do not run a Dim switch. 1 Link to comment Share on other sites More sharing options...
JFranklin Posted December 14, 2019 Share Posted December 14, 2019 21 Candles are a lot dimmer than the million CP modern cars blind you with on the highways nowadays. 1 Link to comment Share on other sites More sharing options...
DB26 Posted December 14, 2019 Author Share Posted December 14, 2019 (edited) Wow thanks for all the replies everyone! First off, I know using the dimming coil would be something I don’t do often, but I wanted to add it back in for originality. I just love putting things back to the way they were from the factory. I can show it off to someone somewhere at some car show and note how dim the lights are and then note how dim they are with the dimmer added in. Second, the picture I used it not my actual switch and coil, it was borrowed from @R.White This is my coil: I was concerned about the fuzzy exterior being asbestos. I know resistors get hot, I was just fishing for any warning from members with much more experience than me. I can clearly see that my questions are a bit over cautious, so I will shed my doubts and run the coil in the car. Edited December 14, 2019 by DB26 (see edit history) Link to comment Share on other sites More sharing options...
Mikefit Posted December 14, 2019 Share Posted December 14, 2019 DBm 26 the coil I have looks a lot like v the one I have. Mike Link to comment Share on other sites More sharing options...
Mpgp1999 Posted December 19, 2019 Share Posted December 19, 2019 If anyone has an old spare dim coil I may be interested. I keep a spare ignition switch under the seat. It is missing the dim coil. Link to comment Share on other sites More sharing options...
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