The Gauge:
Isspro 3975
It has 5 connections at the back:
Instrument light (+)
Instrument light (-)
Signal (sender)
12V Positive (+)
Ground (-)
I found a dangling wire behind the panel. The wire splits into 2 and connects the instrument light (-) and the Ground (-). If the wire is dangling disconnected and touching nothing the gauge reads correctly at half full. Then when the instrument lights are switched on, the gauge goes up to Full but is not illuminated. Now if I touch the dangling wire to ground, the gauge illuminates and reads correctly. Still holding the wire to ground, as I switch the lights off and on, everything works as it should.
What I find odd is that:
1-The gauge works at all with this wire disconnected
2-The gauge reading changes to full as described above
I assume maybe the gauge is grounded in its mounting, so that is why it may work when this ground is disconnected. But why would it go to Full when the light is switched on? I'm just trying to figure out if there is a larger issue, or is this is normal operation. It seems if I simply connect this ground wire then everything will work as it should.
Isspro 3975
It has 5 connections at the back:
Instrument light (+)
Instrument light (-)
Signal (sender)
12V Positive (+)
Ground (-)
I found a dangling wire behind the panel. The wire splits into 2 and connects the instrument light (-) and the Ground (-). If the wire is dangling disconnected and touching nothing the gauge reads correctly at half full. Then when the instrument lights are switched on, the gauge goes up to Full but is not illuminated. Now if I touch the dangling wire to ground, the gauge illuminates and reads correctly. Still holding the wire to ground, as I switch the lights off and on, everything works as it should.
What I find odd is that:
1-The gauge works at all with this wire disconnected
2-The gauge reading changes to full as described above
I assume maybe the gauge is grounded in its mounting, so that is why it may work when this ground is disconnected. But why would it go to Full when the light is switched on? I'm just trying to figure out if there is a larger issue, or is this is normal operation. It seems if I simply connect this ground wire then everything will work as it should.