Gauges

[twilliams_34]

Hi
I currently have a random issue with the oil pressure gauges and volt gauges on my Sealine S28.
The oil pressure gauge seems to vary, it will either be 80 PSI or 30 PSI when on 30 the voltage will be on zero? This happens on both engines but not necessarily at the same time.
I am sure there are Gremlins in the electrics some where I just do not know where
Anyone have any suggestions?

Tony

 

[carlton]

Clean the contacts and try again.

 

[spannerman]

Check the earth on the instruments, if thats OK then check the 12v supply from the ignition switch to the instruments, preferably when its playing up. If this is stable then the fault is after the switch, if it drops at the switch then its further back toward the engine, i.e. harness, connector at engine.
But its unlikely to have the same fault on both engines on the positive side as they are independant, so I would be looking behind the panel for a bad earth first.

 

[Drifter]

It very much depends upon the circuitry but as a rule of thumb the oil pressure as displayed on the gauge is comensurate with the resistance values from the oil pressure sender. With VDO senders & gauges, the oil pressure reading increases as the resistance increases so perhaps the apparent fall in voltage also effects the readings on the oil pressure gauges.

 

[twilliams_34]

Thanks for the tips, looks like I will be checking the earth connections at the weekend. I will you know how it goes.

Cheers