testing water temp gauge,91 Toyota Cressida

Joined
Apr 11, 2004
Messages
3,913
Location
los angeles
The water temp gauge on my son's "91 Cressida never goes over 1/2. If I disconnect the water temp gauge wire,it'll go all the way down. I want to know if itis accurate. Is there a way to trick the needle to go up? I've tried letting it idle without a fan, but it doesn't move higher than half and I don't see any overheating symptoms. can I maybe add a few volts to the wire? thanks.
 
Joined
Jan 22, 2011
Messages
7,861
No dash gauge has ever proven to be reliable. I doubt there's an issue with the operating temperature of the engine. A new sender is not very expensive and I would try that. If you want reliable accuracy, install an aftermarket gauge which indicates actual degrees.
 
Joined
Dec 31, 2017
Messages
12,449
Location
SE British Columbia, Canada
Get a laser pointed infra red temperature gun and take temps at the location of your temp sensor and your thermostat. That will give you an accurate temp and then go from there. Those temp guns are very handy devices to have. About $20 to $30 and available at most hardware stores or Amazon.
 
Last edited:
Joined
Nov 30, 2004
Messages
2,861
Location
SD
I don’t know the design of your circuit specifically, but if it’s like I think it is, you can pull the wire off the sending unit and then ground the wire. Then turn the ignition switch on, but once the needle heads toward Hot, shut it off quickly. If you let the gauge peg and just sit there, you can burn it out.
 
Top