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Join Date: Nov 2020
Posts: 15
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Dash lights not working
I removed the dash thinking the bulbs need to be upgraded to LED, but that wasn't the problem. Still no lights. Fuse is fine, so now I'm thinking that there's no power. Anyone have a simular issue? I'm thinking I should check that there's 12v coming out of the dimmer switch.
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Join Date: May 2022
Posts: 18
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Registered
Join Date: Nov 2020
Posts: 15
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Only the three illumination lights are out. everything else works
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Join Date: Oct 2002
Location: Boulder, CO
Posts: 1,205
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The dimmer may have failed, somewhat common. Possibly fixable. If using LEDs you may want a dimmer for LEDs instead as they are IMO too bright for night driving without some dimming.
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LED's dont have much power draw and the dimmer is a variable resistor in series. if you want you can parallel a real bulb with the LED and hide it, or use a resistor of the same value. Yes you can try to check that variable resistor with a meter too, it might have dead spots due to wear. dirty wiper, etc.
when you have a variable resistor in series with the load, it has a voltage drop through the resistor, and a resistance through the load and the two voltage drops should add up to 12V since you have put LED's in they have very little load and that might affect the division of the voltage drop. Personally I'd put in bulbs not LED's but if you like the color of LED's I'd just make them have the same voltage drop as a bulb by adding a resistor in series with each LED to keep those voltage drops in proportion. I'm not really sure if the LED's will take to dimming well. they may just require a certain voltage and if they see that , come on to near full intensity. If you like you can experiment a bit and see what happens with them out of the car and in a similar circuit. watch what happens to one as it is fed a range of zero to 12 V. you can put your meter probes across the dimmer and put it on ohms, with power off and check the resistance, that should show if you have dead sots or a problem with continuity due to dust dirt etc. are the right bulbs hard to get or do you just want the whiter light of LED's? I think right now with only the LED's hat you have is the same variable resistor but very few amps running through it and that will make it seem very sensitive. If it's carrying a bit higher amperage then dust and whatnot may be less of a problem than with only a teeny amount of load (current in Amps) running through the dimmer switch. It's designed to work with the OEM bulbs which have a tiny bit more current draw. I think what I'd do first s make up a breadboard circuit and use the two wires from the dimmer in the circuit, but just hook up the bulbs without them being installed and see that the electrical mod you are making works before worrying about installing them. You might sub in little resistors of about the same value as the OEM bulbs to see if that helps. I suspect each bulb is in parallel with each other so that if one burns out it wont take the others out. If the bulbs were all in series and one burned out you'd have no dash lights. Last edited by Monkey Wrench; 05-08-2023 at 09:17 AM.. |
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