Hi
I have a couple of used speedo's and would like to illuminate
them as i want to hang the on the wall in my work shop.
What i need to know is what pins in the socket is the pos and neg.
Thank you.

dave king

 

If you're talking about the center-mount speedo, then unfortunately it's not that simple.
The GM module controls the headlights/taillights. When it turns them on, it sends a BUS signal to the center speedo which then illuminates the instruments. So the only way to get it to illuminate is to connect it to a CAN emulator and feed it the right information.
However, if you have a steering column mounted tach or speedo, then it's as simple as you' imagined. The center mount speedo just feeds those a 12V signal to illuminate.

 

Thank you for that.
Just as i thought