Hello all, I was wondering since I have some new odometer parts on order and I will have the instrument cluster out anyway, I have a Volvo small tachometer that I would like to install. I know Volvo had lots of extra wires in there harness, but I have never done this before, so what wires am I looking for? what color, and so forth? any info you could give me would be appreciated.
Thanks, and God bless.
mike

 

Look for a red/white wire with a plug end, power might come from plugging it into your clock. The red/white plug should currently NOT be plugged in.

Ive installed several big tachs n little clocks but never the other way around, the little ones are a bit rare.

 

not sure I'd power it by plugging into the clock, as thats 'always on' power, and a tach you probably want switched power. also probably wants to be connected to the dashboard light dimmer circuit so it will light up at night.

 

If I remember right there were two wires that went to it, one for the light and one for some kind of pulse to give it the RPM's to work.

 

The red/white wire is what provides the RPM signal.

 

well I took a good look at at the back of my small tach and it requires a large plug thing. I found three unused wires behind the inst cluster and all have male ends, I need a 4 plug female end.

 

sounds like you're missing the harness connector for it.

the 4 pins are likely ground, circuit 15 (switched power), dashboard dimmable lights, circuit 1 (the red-white timing wire, which comes from the coil). your mission, should you choose to accept it, is to figure out WHICH of those pins on the tach is what, and find a suitable connector, or shrinkwrap 4 seperate pin sockets onto wires, and figure out where to get all those signals from.

I've never seen a small tach in the 'expansion cluster' next to the main instrument cluster, so I can't be of any more assistance beyond that.