Temp Guage Stopped Working

jka

Seaman
Joined
Jun 13, 2004
Messages
64
My Temp Guage on the 4Winns 94 Horizon, 5.0 EFI stopped working this past weekend. Any thoughts on what may be the issue? Engine was running fine and didn't overheat during a 2 hour trip.
Thanks for your help.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Temp Guage Stopped Working

Could be the gauge, the sender, or the wiring to it.
Turn the ign to run, then remove the wire from the sending unit on the engine, and touch it to a good clean ground. The gauge should peg out to the hot side.
If it does, the sender is bad. If the gauge doesn't move, check the wiring to the gauge. If you have power, and good ground and the sender wire checks ok, then the gauge is bad.
 

MJ76

Petty Officer 3rd Class
Joined
Sep 17, 2006
Messages
85
Re: Temp Guage Stopped Working

First I would check to be sure there is power to the gauge (probably a purple wire) when the ignition is turned on. If so I would measure the resistance at the gauge between the sender wire (probably tan) and ground as you warm up the engine. A typical sender will read out values in the range of something like 40-240 ohms. Obviously it should start out at a certain value when the engine is cold, and increase (or decrease, I can't remember which) as the engine warms up. If it does that, and the gauge doesn't move, you have a bad gauge. If not, repeat the test at the sender, which is located at the thermostat housing. There may be a couple things there, a cooland temp sensor for the EFI, for example. The sender you are looking for should have a single wire, the same color wire you saw at the gauge. If you get no change there, you should replace the sender.
The other easy thing you could do is ground out the sender lead with the key on, while watching the gauge. This would be an easy way to condemn the gauge - it should spike when the lead is grounded. Hope this helps.
 

jka

Seaman
Joined
Jun 13, 2004
Messages
64
Re: Temp Guage Stopped Working

thanks guys. I'll follow your leads on this! Always great to get good advice.
jka
 
Top