I just installed a tranny temp guage and an A/F guage in my car yesterday and neither one work. I Checked all my grounds and power wires with a test light and they they all seem to be fine. I wired the A/F guage to the purple C20 wire comming from my PCM. The guages aren't showing any readings and they don't light up at all. Could it be because I spliced all the wires together like the ground wires and the power wires? Any suggestions?

 

how do you have the power wire hooked up. What did you tap into?

 

I tapped into an orange power wire under my dash, my e-cutout and my radar are also tapped into this wire. It only has power when the ignition is on.

 

what voltage do you get to the power wire at key on?

 

Maybe you should check the fuse. That's a lot of things to run off that one wire.

 

All the fuses are fine, my radar and my e-cutout still work fine.

 

then you must not have 12v to it.....if not that then check your grounds