Replacement Headlight Switch to Dim LED Guages

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72Duster440

72Duster440

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I couldn't really find anything that specifically said it could, but I am looking for a replacement headlight switch that is also able to dim aftermarket guages with LED lights in them. The factory switch obviously doesn't have that low of resolution and it's either on or off, but getting them on without the dome light coming on is difficult. I have Autometer Ultra Lite guages that I switch to LED bulbs. Autometer has a separate add on unit to dim them, but I'd like it to all be controlled by the headlight switch.
 
It is not the 'resolution' but the resistance. The LEDs draw far less current. I will guess that some experimenter needs to come up with a solid state circuit that can drive the LEDs---that is the stock factory dimmer feeds the module, and the module translates that to something the LEDs can "use." A "stop gab" measure would be to put a load resistor across the orange buss to ground, but that is a chicken way around the problem.

You MAY (I don't know don't use them yet) be able to add series resistance to get it to work. You could experiment with that by pulling the INST fuse and clipping in a test resistance at the fuse clips. You could get "some idea" of this if you can "rig" a test to the lamps to determine what voltage range they need. IE "rig" some flashlight batteries in series to determine what they need for voltage to dim "as you like". Measure the current draw of them at that voltage. Then measure the resistance of the dimmer. last, you will have to calculate what series resistance, with whatever resistance of the dimmer, at 12V will drop the voltage that you arrived at earlier.

If I were younger I might be able to do some of this. Anything I do anymore takes 10X the time it used to, seems like LOL
 
IMHO, if you are going to add series resisters or load resisters to the LEDs why use LEDs?

I like the idea of a controller controlled by Dimmer!
 
Well series resistors DECREASE current flow so if they can be made to work, they aren't quite as bad LOL
 
I knew I could add resistors to increase the load, but the point of going LED was to reduce the load, every other bulb in the car, including headlights are LED.

Autometer sells their dimmer for LED, but I don't want an add on box. I figured some newer cars headlight switch may be able to handle the reduced load better, but I couldn't find anything that specifically stated it could.

MODULE, DIMMING CONTROL, FOR USE WITH LED LIT GAUGES (UP TO 6)

I dont even necessarily need to dim them, just want them to stay lit without having to turn my dome light on. Right now its hit or miss, maybe even a new replacement factory switch would take care of that.

I ran out of bulbs, but heres the difference between the incandescents the Autometers came with and the drop in LED bulbs.

20210819_211245.jpg
 
I don't know where or how you are going to find a "drop in" switch to magically fix this problem. Frankly I think you are banging your head on the wrong door.
 
If you don't need them to dim or you wanrmt them dimmed a specific amount you could run them off of a separate cir.
 
LOL you are still going to need something to dim them......resistors/ stand alone module, or "maybe" a rheostat. Not sure that is really going to be easier...................
 
Whatever you say bud, try reading where I said "I don't even necessarily need to dim them, just want them to stay lit without having to turn my dome light on."
 
Are you sure the reostat in your OEM switch is good? I dont think it should turn the LEDs off right behind the dome lamp position. Its possible to bypass that reostat too. Lights will be full on regardless where the knob is tuned to. this doesn't effect the dome lamp.
 
Disconnect the neg' battery cable. Take the switch out and have a look at it. You'll see a slither of metal that is a conductor with a hole in it that made is easier to bend. It will peel right out of there and straighten out. The other conductor is directly beneath that hole at the center of the rheostat. I soldered my bypass jumper through that hole so my mod is on the switch itself. I won't toss a otherwise good switch because the illumination rheostat has failed. I dont wear eye glasses, don't need the dimmer. Anyway... The cars wiring isn't altered. If I wanted to get out a ohms meter I could finger out where a bypass jumper would belong above/before the harness connector but that just wasn't necessary. The next owner can plug in a new switch and mod I did goes in the garbage.
 
I have found that if you leave one regular bulb in, the dimmer will work with LEDs. My after market gauges over the console have incandescent bulbs in them. Maybe leave one in your stock radio.
 
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