Guages, Working or Not?

[Hookshurt]

Is there any testing tool or means to determine if a guage (water temp, Oil Pressure, Volt, etc.) is actually working other than installing it? I am rewiring the dash panel and would really like to make sure that the guages are good before I finish the task and install. Some were and some weren't working prior to tear down, but the prior owner advised me that they may have been wired and/or grounded incorrectly so I'm basically at square one. Any advise or options for testing? Thanks, Mickey

[In Memory of Vicroy]

Electric gagues read the variable resistance in the sender, so they are nothing but volt/ohmeters. For example, the temp sensor has more resistance when cold than hot. If you put a low voltage, say less than 12vdc, thru the meter it should move. If you have access to a variable voltage power supply you can test the full range of the gague. The written specs for the gague (avialable from maker) will show the voltage range and resistance. On the other hand, as cheap as electric gagues are it may not be worth the trouble.

UV

[Bruce]

On 90% of gauges, feed +12 and -12 to the appropriate terminals on the gauge.

Then GROUND the sender wire. Guage should go full range. This will test the meter movement.

[Hookshurt]

Thanks guys. I'll give it a shot.

[gplume]

Hookshirt

I made a little variable resistor test board to trouble shoot guage or sender. If I am not mistaken, most of the senders are around 180 ohms (can't remember exact value) . Its been a while, but I think I used somthing a like a 0-500 ohm variable resitor (something sitting around the workbench at work is what I grabbed). I am pretty sure you can get the specs online for what your guages want to see full scale in terms of a resistance range. Dial the resistor, and chech the guage. If no movement check the power and ground, then the guage.

Giff