So when I had my car in for its stage II upgrade, I figured that I would just let the shop install my boost gauge for me. The gauge worked fine when I left the shop, but ever since then it doesn't work like it's supposed to. For example, when in idle, the needle reads "0". When I get on the throttle it reads something like 25psi. The gauge almost never goes into vacuum. Also, the light on the gauge is always on, with or w/o headlights on.
I took a look at the wiring today and this is how the shop has it wired up,
Gauge Wiring Clock Wiring
Red - Constant 12v----------> Blue/red tracer - Constant 12v
Pink - Ignition 12v---------->Yellow/green tracer - Ignition 12v
Grey - Illumination------------>White/red tracer - Illumination
Black - Ground---------------->Black - Ground
Brown - Analog (not connected)
White - Analog (not connected)
The shop did solder the gauge wires into the clock radio harness. I tried wiggling the wires with the car running and nothing changed.
Now, searching on this site, I see that people have wired their gauges up to the radio/hvac wiring harness. Is this a better place to tap into? Is this the correct diagram for wiring up an analog boost gauge,
Gauge Wiring Radio Wiring
Red - Constant 12v------->Blue/red tracer - Constant 12v (radio harness)
Pink - Ignition 12v------>Green/orange tracer - Ignition 12v (a/c harness)
Grey - Illumination-------->Violet - Illumination (radio harness)
Black - Ground------------>Black - Ground (radio harness)
Any help with this would be great!