C4 Electrical experts needed here!
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,512
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From: Franklin IN
C4 Electrical experts needed here!
Does anyone know what the is the range of the temp sender for a 93? Am I correct in assuming that it is a resistance device? As it gets hot the resistance goes up or down. Please enlighten me. thanks!
Racer
Joined: Sep 2014
Posts: 429
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From: Brooklyn, MI
The hotter it get the lower the resistance. 55 ohms 280 degrees and 1400 ohms 100 degrees give or take a few. The rule of thumb is open (high resistance off scale high. Short ( no resistance is off scale low.
Pro
Joined: Mar 2009
Posts: 702
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From: Middletown Delaware
The coolant temp sensor is called a thermistor, look that up and you will find your answer on how it works. - Ozz
Team Owner
Joined: Sep 2003
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The analog gage in the later C4's I believe 55 OHM is considered HOT and something 1400 OHM is considered COLD - it varies widely between the extremes. Some aftermarket replacements mention different "reference" specifications.
You DO NOT rely on the analog gage in a later C4.
Last edited by WVZR-1; Apr 29, 2015 at 02:46 AM.
Team Owner
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You don't need to be concerned about the '06 other than the CTS for the "RUN" function for the PCM/ECM. For the gage you're only concerned about the COLD - HOT values of a sender as I mentioned in your other thread. You've only got a DK GRN wire to the gage sender I believe even though some of the later LT engines used a 2 terminal sender. Is that correct?
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
You don't need to be concerned about the '06 other than the CTS for the "RUN" function for the PCM/ECM. For the gage you're only concerned about the COLD - HOT values of a sender as I mentioned in your other thread. You've only got a DK GRN wire to the gage sender I believe even though some of the later LT engines used a 2 terminal sender. Is that correct?
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Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
According to what I have found the sensor in the 2006 truck motor reads the same as in the 93 Vette motor the pig tail is different and will need to be changed but the sensor should allow the gauge to work properly. here are the values for the truck sensor:
Temperature
Resistance
50° F (10° C) 5670 Ω
68° F (20° C) 3520 Ω
86° F (30° C) 2238 Ω
104° F (40° C) 1459 Ω
122° F (50° C) 973 Ω
140° F (60° C) 667 Ω
158° F (70° C) 467 Ω
176° F (80° C) 332 Ω
194° F (90° C) 241 Ω
212° F (100° C) 177 Ω
Temperature
Resistance
50° F (10° C) 5670 Ω
68° F (20° C) 3520 Ω
86° F (30° C) 2238 Ω
104° F (40° C) 1459 Ω
122° F (50° C) 973 Ω
140° F (60° C) 667 Ω
158° F (70° C) 467 Ω
176° F (80° C) 332 Ω
194° F (90° C) 241 Ω
212° F (100° C) 177 Ω
Team Owner
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Yes the 93 has a two wire coolant sensor. One is Black and is a ground the other is yellow and goes to the ECM. Hmm, the pig tail of the 2006 engine has a yellow and black wire coming out of itIf I could find out the values for the 2006 engine I may be able to change out the wire terminal end (weather pack) and use the 2006 sensor to feed the 93 ECM. That would be awesome!
I was only mentioning that it's possible that the LT had a two terminal sender for the gage BUT that it functions also as a single pin sender if you were wondering the why I pointed you to a single blade sender.
You need to accomplish the RUN functions using something other than the LT ECM.
According to what I have found the sensor in the 2006 truck motor reads the same as in the 93 Vette motor the pig tail is different and will need to be changed but the sensor should allow the gauge to work properly. here are the values for the truck sensor:
Temperature
Resistance
50° F (10° C) 5670 Ω
68° F (20° C) 3520 Ω
86° F (30° C) 2238 Ω
104° F (40° C) 1459 Ω
122° F (50° C) 973 Ω
140° F (60° C) 667 Ω
158° F (70° C) 467 Ω
176° F (80° C) 332 Ω
194° F (90° C) 241 Ω
212° F (100° C) 177 Ω
Temperature
Resistance
50° F (10° C) 5670 Ω
68° F (20° C) 3520 Ω
86° F (30° C) 2238 Ω
104° F (40° C) 1459 Ω
122° F (50° C) 973 Ω
140° F (60° C) 667 Ω
158° F (70° C) 467 Ω
176° F (80° C) 332 Ω
194° F (90° C) 241 Ω
212° F (100° C) 177 Ω
Last edited by WVZR-1; Apr 29, 2015 at 08:43 PM.
Race Director
Joined: Apr 2002
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From: Anaheim CA
The only exception is the CTS that the ECM uses. It uses a two wire CTS and does some electronic and software magic to make it more accurate.
Team Owner
Joined: Sep 2003
Posts: 25,373
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As I mentioned in my post, the numbers are the same for ALL the coolant temperature sensors (and the MAT sensor too). The physics doesn't change just because a particular sensor has a different function.
The only exception is the CTS that the ECM uses. It uses a two wire CTS and does some electronic and software magic to make it more accurate.
The only exception is the CTS that the ECM uses. It uses a two wire CTS and does some electronic and software magic to make it more accurate.
I believe a gage check of an early digital cluster is done 1600/LO to 75/261* with a +/- of 6*. There are specific values for various TEMPS mentioned but the +/- 6 still applies.
OP - I'd do this if it were my conversion I think or it's maybe my first thoughts. I'd buy an M12 X 1.5 single pin sender intentioned for a gage with advertised specs of something 55 - 1400 or close. Once I had the car running as I wanted I'd use a scanner to confirm the TEMP indication on my analog gage vs. the CTS (for the PCM/ECM) and "drive on".
Last edited by WVZR-1; Apr 30, 2015 at 09:33 AM.