View Full Version : Testing a Temp. gauge

Tom Wortham
10-12-2004, 03:49 PM
For the many years I have owned my 86 MC... the Temp. gauge never seems to move. I have check the wiring behind the dash and to the engine... all looks good. Any ideas how to trouble shoot if it is a short in the wiring, gauge itself, thermostat. :uglyhamme Other wise boat runs good.... and I change the impeller out every season. Thoughts :confused:

10-12-2004, 04:30 PM
Is it safe to assume you have opened the thermostat housing and made sure there is a thermostat? All you have to do is go find your wife's candy thermometer, bring water to 140 degrees and stick in the thermostat and see if it opens. Then raise it to 160 degrees,then again at 180. If by chance you don't have a wife or a candy thermometer, or both, then go buy one at the grocery store. No not a wife dummy,8p a candy thermometer. If that all works, then you need to see what is wrong with the wiring? Could be you are not getting enough juice to cause it to register.:D


Tom Wortham
10-12-2004, 04:40 PM
Thanks for thre response. I do have a wife and a candy thermo. So I'm good to go there. :D
I have NO idea if there is a thermostat in the housing or not. I'll find out. Hard to get to? I have a 351 Ford. :confused:
If it does not open by the time it gets up to 160... bad therostat?

10-12-2004, 06:08 PM
If the wire to the temp sender was shorted, it would peg the gauge on the high side. If it's open or the sender is open, it won't move unless the connection is intermittent. You should also check for impeller chunks stuck in the thermostat. That would keep it from closing fully.

10-13-2004, 09:07 AM
I had similar issue. Problem was missing thermostat. Tested temp gage using hair dryer.