Richard Cope Posted June 28, 2020 Report Share Posted June 28, 2020 I would like to thank everyone earlier today for your comments on my headlight switch question. Have one more switch question (Panel Switch), would appreciate your comments. The switch will be controlling 4 small dash lights and a dome light above the rear window. In the attached photo my original switch has a knob and the second is an NOS, part # 69594. The switches have a two position pull, when fully extended the bulbs are brighter. The original works but the shaft is somewhat bent. I would like to use the NOS switch with a 12 volt negative ground system., doing so would allow me to use the stock knob and have two levels of brightness. This switch isn't as rugged as the headlight switch, however wasn't intended and won't be handling as much load. Any thoughts on how the resistor would perform, would it require changing?. Has anyone used a similar panel light switch with 12 v? Thanks Rich Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 28, 2020 Report Share Posted June 28, 2020 Very generally speaking, switches and resistors won't notice 12v vs 6v or which ground you are running. So running 12v positive ground thru this switch should not be an issue. Will you have two levels of brightness, yes. But will the difference be enough to matter? Unknown since we don't know the value of the resistor. If we knew that I could calculate the wattage difference between bright and dim at 12v for you. Well, I'd need to know what bulb(s) and how many of each you were going to feed with this switch. Don't forget the bulbs need changing when going to 12v. Quote Link to comment Share on other sites More sharing options...
Richard Cope Posted June 28, 2020 Author Report Share Posted June 28, 2020 Many thanks, I can get the bulb #s tomorrow however the value of the resistor is unknown. Using the stock knob is the important part, if the brightness changes is a plus. Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 28, 2020 Report Share Posted June 28, 2020 Do you have a multimeter that you can use to measure the resistance of the resistor? Without knowing the resistor's value I can't do the math. Quote Link to comment Share on other sites More sharing options...
greg g Posted June 28, 2020 Report Share Posted June 28, 2020 If you remember ohms law, you will see amps decrease as voltage increase so putting 12v through a 6v switch is half the resistance load it was designed for. Quote Link to comment Share on other sites More sharing options...
Richard Cope Posted June 28, 2020 Author Report Share Posted June 28, 2020 Can't get my ohm meter to work correctly, however almost finished making up wiring harness for dash. Will test out tomorrow with bulbs 1 Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 28, 2020 Report Share Posted June 28, 2020 Well, the proof is in the pudding. Calculating the difference isn't nearly as accurate as seeing the difference, lol. Reality always trumps theory. Let us know. Quote Link to comment Share on other sites More sharing options...
Richard Cope Posted June 28, 2020 Author Report Share Posted June 28, 2020 Works great. Switch only controlling 3 bulbs, 2 are small & can use either # 55 (7v,2.9 w) or # 57(14v, 3.5w) in the dash and a larger single contact bulb as a dome light #1156 (12.8v). The dome light is on a separate switch & not used that often. On the first trial used 2 #55 bulbs & the 1156. The 55s bulbs were much brighter as compare to using 6 volt, switch did noticeably increase / decreased the brightness. Next tried two # 57 bulbs and the 1156. The light intensity was much similar to what the 6 volt produced with only the 57 bulbs lit. When the dome light was turned on, will have to use full brightness. With the 57 bulbs the switch still controls brightness, however not as much. Will probably use the 57 bulbs as the light intensity is what am use to. Thanks RC 1 Quote Link to comment Share on other sites More sharing options...
Andydodge Posted June 28, 2020 Report Share Posted June 28, 2020 When I installed the V8 etc in my 1940 Dodge in 1973 I kept the original gauges and switches including the original headlight switch which is the same style that you have as pictured in the other thread, its always worked fine with 12 volts and I have no reason to swap it for something else..........its the switch pictured on the right side with the chromed knob which is not original but better looking than the disintegrated plastic original knob..........lol.........andyd Quote Link to comment Share on other sites More sharing options...
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