Dimming Illumination for triple gauges

Hi, I installed water temp, oil pressure, and ammeter gauges in my 71 Grande tonight. I went to install the illumination wires for the gauges by splicing into the air conditioning and heater control box light so that way I can dim the gauges with the dimmer switch. The gauges would not light up at all. I tried switch my ground I was using to several different locations and no luck. Is the wire that supplies that bulb supplying enough voltage to power those gauges lights? Where do you guys wire yours into?

First off, you cannot push current to devices, you can only supply voltage.

You need to tap into a blue/red wire on your main underdash harness for the lights and you also need to provide a ground to each of the two bulbs.

A good place to do that wire tap is the light feed to the radio. It is right where you will be working.

A good place to do that wire tap is the light feed to the radio. It is right where you will be working.

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Thanks for the tip. What color is that wire that feeds the radio for illumination? My radio is missing and I can't make sense of the wiring diagrams on the internet. Any pointer would be appreciated.

As I said, illumination is blue/red.

I did the aftermarket tri guage and tapped off

the radio light wire.

check wires for power with lights on with a test light.