I can't seem to locate the temperature sending unit. my temp readout (digital) stays on LO, which this car never runs. I found a unit on each side of the engine, but am not sure which is which.....Thanks again, forum......... :seeya

 

The gauge temp sender is at the front of the engine just under the Throttle Body intake. :thumbs:

 

Passenger side of block :thumbs:
:cheers:
The one on the front of intake is for ECM input


[Modified by AGENT 86, 5:38 PM 3/13/2004]

 

My 86 has the temp sending unit on the right (passenger) side of the block closer to the firewall between and just below the sparkplugs. Check to see if the wire came off and is down by the starter. That wire sends the signal for the dash readout. The sending unit that is under the throttle body is the coolent temp sensor for the ECM.


Good luck..

:thumbs:

 

i gotta agree with the first reply. the sensor on the side of the motor between the plugs is for the ECM to tell the big fan when to come on. if you unplug that, the fan will always run when the car is on. the sensor below the throttle body sends the signal to the dash. the chevy service manual seems to confirm this as well. good luck. it drove me :crazy: when my oil temp guage didn't work. had to hunt down that sender in the manual...its not really even mentioned, but there is ONE figure that shows where it is. i always got a LO ready as well. a little giggle on the wire cleared that right up :thumbs:

 

Orlando85UCFvette,

What side of the engine are you refering too? I also have a sensor that controls the fan cycle but this sensor is on the left (drivers) side. As for the sensor under the throttle body, It's a coolent temp sensor but doesn't have anything to do with the readout on my dash. I've replaced it twice in 10 years.
Both times the result of a error code after getting the service engine soon lite.

 

:iagree:
That is correct :thumbs:




[Modified by 86PACER, 2:01 AM 3/14/2004]

 

vetteboy88:seeya
According to the Service manual on my 86, (should be the same as your 88). the sensor that sends the temp to the dash guage is the one on the passanger side between the #6 and the #8

Here is how to test it the way the Service manual shows.

If your coolant temp shows low when engine is hot (which is what you problem is) do the following:

1. Remove the "Dark Green" single wire connector from the sensor.(It's threaded into the passenger head between the #6 and #8 spark plugs and has a single Dark Green Wire connected to it.)

2. Connect a fused jumper from the connector to ground.

3. Put the ignition swith to the "RUN" position.

4. If the display now shows HOT , the wiring and display are good and now pefrom steps A-C. If is still shows cold skip to step 5.

a.) Measure the resistance from the sensor to the terminal ground.

b.) If the restistance is infinate ohms or less that 40 ohms, replace the coolant sensor.

c.) If the resistance is good, look for a bad sender wire (The Green One) and follow it checking for damage.



5. If the display still reads cold with the fuses jumper in place, look for an open circuit along the Green Wire back to the Instrument Panel.

I hope this helps you man. Good luck :thumbs:

:auto:


[Modified by 86PACER, 2:18 AM 3/14/2004]

 

thanks for the help!!!!!!!!!!!!!! :cheers:

 

thanks for the help on this one guys...I'll get right on it!!!!!!!!!!!! :smash:

 

85
Temp sending between 1-3
Aux fan switch between 6-8