1970 XR7. I have my instrument panel out of my car and I installed new bulbs and sockets for all the lights. I bought a new headlight switch and was attempting to see if everything was working before I reinstall it. I can get the 5 gauge illumination lights to light up and go off by turning the headlight knob, but none of them will dim. I am only using a battery charger to energize the circuit with negative to the gauge cluster and positive to the headlight switch terminal B and then a wire from terminal I to the gauge cluster circuit board 2nd copper strip. Am I missing something that would make the dimming feature work ? ( they do go on and off with this setup, just won’t dim)
LED lights or bulbs? Also, most battery chargers are not designed to replace the battery, only to charge it. You need the battery in circuit for the charger to work correctly.
Regular 194 bulbs, and I also tried direct to battery with no change. I also purchased a second new headlight switch and still no dimming function. I also tried a ground to the headlight switch along with grounding the instrument cluster. I was wondering if the voltage regulator, instrument panel needs to be hooked up for the dimming function to work
The dimming function is simply a variable resistor (rheostat) that increases and decreases series resistance to the bulbs as you rotate it. I would restore everything to the factory configuration and if you still have no dimming, it about has to be either a bad headlight switch rheostat, or the wiring to the headlight switch is messed up.