Oil pressure gauge

[VSteve]

I just fitted an oil pressure gauge to my VT and it has a weird problem. With any electrical load the oil pressure reading on the gauge goes down. For example with the car idling and everything off it sits at about 53PSI. If I turn on the headlights it will drop to about 45, put on the high beams 30 and with the heater fan on you can get it to 0 PSI. What would be things I should check, possible causes?

 

[acarmody]

Maybe your headlights are oil lamps?

Where did you hook up the positive power too?

 

[VSteve]

Maybe your headlights are oil lamps?

Where did you hook up the positive power too?

Positive is connected to the car phone power connector that is on the passenger side tucked under the center console.

 

[sssmechanicholdenbrisb]

sounds like voltage drop
check that you have the same roughly 14volts all on and all off e.g. idle and idle all lights on
if less than 13 needs altenator looked at next check earths e.g. on engine and on battery BOTH ENDS to see if tight. if not any of the above connect a wire form you engine metal straight to the battery negative terminal if this fixes problem buy an earthing kit from ebay and fit it...