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anyone can guide me how to do that with only the dash harness hooked up (and not connected to the engine compartment harness). I tried to follow the instrument panel wiring diagrams but no succes yet. I tried to measure variable resistance but could not find it...What I need is the feed wire (on the fuse box side) for 12V that goes to the dim resistor in the light switch
The voltage comes from the fuse box on the brown wire of the tail light fuse (second from bottom). It goes through the dimmer rheostat and then up to the instr lamp fuse (third from bottom) on the dark green wire.
If you pull those two fuses and measure between the right side of the tail fuse clip to the left side of the instr fuse clip, you'll be measuring only the rheostat resistance.
You don't really have to pull the fuses, I just like to isolate other possibilities when measuring resistance. It should read the resistance with fuses in place.
The voltage comes from the fuse box on the brown wire of the tail light fuse (second from bottom). It goes through the dimmer rheostat and then up to the instr lamp fuse (third from bottom) on the dark green wire.
If you pull those two fuses and measure between the right side of the tail fuse clip to the left side of the instr fuse clip, you'll be measuring only the rheostat resistance.
You don't really have to pull the fuses, I just like to isolate other possibilities when measuring resistance. It should read the resistance with fuses in place.
That worked great. Full CW the dash backlit is off, full CCW it's on. I installed LED's, the rheostat is too low to change anything to the brightness.
In which lead can I add some extra resistor for the dash lights? My best guess is the (grey) lead on the 'right' side of the in instr fuse ?
Last edited by alexandervdr; 07-26-2016 at 09:36 AM.
I have no experience with LED's, but if all you want is to add resistance to the bulb circuit, either in line with the dark green to the fuse or with the gray where it comes out of the fuse box before it splits to the bulbs. In other words, in SERIES with the instr lamp fuse.
I have no experience with LED's, but if all you want is to add resistance to the bulb circuit, either in line with the dark green to the fuse or with the gray where it comes out of the fuse box before it splits to the bulbs. In other words, in SERIES with the instr lamp fuse.
TNX. I may add just a resistor (simple) or a LED specific regulator. I'll try the simple&cheap thing first ;-)
Your best bet would be a DC-DC Buck Converter. You can get them on Ebay for $3.50 U.S. If you like, I can send you a link to the one I bought.
I bought some already (always handy) , but if a resistor can do it I prefer that. Less likely to break and less cumbersome to install. I did test install a resistor that seems to be about what I need. I will see how that works out later this evening in the dark.
Yes, please send the link through. Tnx
07-26-2016, 08:37 AM
how to test dash dimmer on 64
