I recently picked up a different clock along with a new genuine voltmeter for my 84 944, but I need some help referencing some wiring on a car that has a working clock. Specifically, I need to know if the clock always has power (which I'm 99% sure it does) and I also need to know what voltage is going to the clock (do I need a resistor or is it just battery voltage?).

I originally had ac in the car, but that has since been removed along with the climate control dial. I got a voltmeter to fill the hole in the center. What I would like to know for this is what ignition battery source is close to the gauge so that I can piggy back off of it

 

The analog clock in the early cars (and 924S cars) runs on 12 vdc and a ground. The 12 vdc can also be tapped for the voltmeter gauge.

 

​​​​​the clock is a constant 12v correct

 

Yes... I was wrong in my prior response, you will want a switched 12 volts for the voltmeter.

 

Actually, the clock has un-switched power.

 

Ok

 

I did this to my car also. I remember using one of the AC plugs for the proper 12V source to the voltmeter. The only thing is it moves when the turn signal is on. Probably should have searched for a better source or ground, but at least it works fine.