Where to buy water temp sensor 1956 cadillac

[Twan-Sloot]

Hi guys,

The water temp gauge in my car would always go up 1/3 of the way with the engine completely cold, after warming up it would only go up another half of an inch and that was it, I thought maybe it’s a faulty temp sensor, so I replaced it with an ac delco replacement not original. Well now my temp gauge will go up 1/3 like it used to but once driving the car the temp gauge wil display big overheat whilst I can just hold my hand on the radiator without burning my hand.

Where’s the problem, did I just bought te wrong sender unit and was the problem in my gauge after all?

[J. Gomez]

Hi guys,

The water temp gauge in my car would always go up 1/3 of the way with the engine completely cold, after warming up it would only go up another half of an inch and that was it, I thought maybe it’s a faulty temp sensor, so I replaced it with an ac delco replacement not original. Well now my temp gauge will go up 1/3 like it used to but once driving the car the temp gauge wil display big overheat whilst I can just hold my hand on the radiator without burning my hand.

Where’s the problem, did I just bought te wrong sender unit and was the problem in my gauge after all?

This particular topic has been discuss under several few threads here are a few;

http://forums.cadillaclasalleclub.org/index.php?topic=148740.msg385721#msg385721

http://forums.cadillaclasalleclub.org/index.php?topic=150835.msg400486#msg400486

http://forums.cadillaclasalleclub.org/index.php?topic=141462.msg337961#msg337961

The new replacements although advertised as equivalent to the OEMs have a lower resistance across the temp range and are not equivalent with the older temp gauges.

As you review these threads the fix is to place a resistor in series with the temp sensor and gauge to compensate for the lower resistance value of the sensor.

HTH

[Twan-Sloot]

This particular topic has been discuss under several few threads here are a few;

http://forums.cadillaclasalleclub.org/index.php?topic=148740.msg385721#msg385721

http://forums.cadillaclasalleclub.org/index.php?topic=150835.msg400486#msg400486

http://forums.cadillaclasalleclub.org/index.php?topic=141462.msg337961#msg337961

The new replacements although advertised as equivalent to the OEMs have a lower resistance across the temp range and are not equivalent with the older temp gauges.

As you review these threads the fix is to place a resistor in series with the temp sensor and gauge to compensate for the lower resistance value of the sensor.

HTH

Thank you, great info.

Read through those threads and I contacted Jason to get a used working corect one.

Many thanks!

Twan

[bcroe]

You might find a resistor value that will make it read correctly at normal
operating temp.  But it will probably have increasing error farther away
from that temp.  I suspect the resistance might be off by some
multiplier like 1.25.  Could be corrected electronically, but a pretty messy
problem.  I use the small, 270 degree gas tube gauges.  Bruce Roe

[fishnjim]

Is it overheating?   Or you just didn't trust?
I suspect its the sensor since you didn't mess with the gauge.   Not likely to go bad all of a sudden.   
They changed them as said, but I was able to still get the right A/C one a few years ago, I recall from Rock Auto.   I think I have the orig and it was working.   I can probably look up the part number, if I kept the box.   The one with the single round connector pin on top?   
If you have a DVM/power supply and a water bath you can check the sensor output against the specs.   That'll tell you if the gauge is OK.   Any competent instrument shop could do that.
Or just put the old one back in and see if it goes away.   These are not that precise, but you can stick a (metal) thermometer in the radiator and see what temperature it runs at.   Just take the cap off before you start.   You don't want to get scalded opening a hot one.