Installed the fuel pressure gauge about 2 years ago. I started getting occasional erratic readings. Turns out that it was just a wire problem on the gauge. The gauge light shorted out (or something)and quit working. Without the light connected, pressures are 13-14 at idle and 10 at 75 mph on freeway.
Got a new light, but when I put it accross the +/- of the gauge, the gauge pegged.
I'm guessing that I will need to run the light on its own power supply and not shared with the gauge?

 

Yeah, the light, wired in parallel, will reduce the resistance of the circuit.
1/ 1/R+1/R is the formula. It's basic dc/ resistance formula. Does the guage have a seperate input for the light voltage?

 

It will in the morning.