water Temperature Gauges check
Thread Starter
Racer
Joined: Mar 2002
Posts: 312
Likes: 6
From: Troy Al
water Temperature Gauges check
I recently replaced the water temp sensor for the digital temp gauge on my '93 coupe. I can't believe after just a few drives it's quit! Stuck on 124 degrees. Is there a way to check the sensor? Can I see a varrying change in resistanse as it heats/cools? This is the sensor that is in the water pump.
THANKS
THANKS
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
I can’t believe the sensor is bad either. That would be an uncommon failure mode. It definitely can be checked using an ohm meter and the chart for the temp vs. resistance. I do not have the chart with me currently. It’s a real bear to check to actually get your leads in there to make contact. The pins are recessed and hard to see.
If I had to take a guess I might think the ECM is not processing the data correctly. But you definitely need to go thru the basic checks before making any determination.
Probably one measurement at room temperature with engine cold might tell you enough. I’ll see if I can get some numbers for you or if some one posts them first. If you have your old sensor you can make a comparative check
If I had to take a guess I might think the ECM is not processing the data correctly. But you definitely need to go thru the basic checks before making any determination.
Probably one measurement at room temperature with engine cold might tell you enough. I’ll see if I can get some numbers for you or if some one posts them first. If you have your old sensor you can make a comparative check
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
The Coolant Temp Sensor (assuming that's what you replaced) is like a choke - the colder the read, the greater the fuel delivery and idle speed. If it was stuck at 124, the idle would be high and the engine would probably overheat as it would never reach the threshold for fan control. You don't seem to have that - or do you? Easiest to troubleshoot with a scanner. See what the ECM is seeing then compare it to your display - I'd guess a display issue if nothing else is out of whack.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
The ECT resistance check, a few check points
Temp....Ohms
68*F = 3250
77* F = 2796
86*F = 2238
122*F = 972
158*F = 467
194*F = 241
You can also check for the 5 volt reference voltage on the yellow wire with it un-plugged (not running but ignition on).
I would also check to see if any codes show up that might give you some direction. Use on board diagnostics.
Temp....Ohms
68*F = 3250
77* F = 2796
86*F = 2238
122*F = 972
158*F = 467
194*F = 241
You can also check for the 5 volt reference voltage on the yellow wire with it un-plugged (not running but ignition on).
I would also check to see if any codes show up that might give you some direction. Use on board diagnostics.
