Intrument cluster showing false or no readings.

there is no fuse. you may have a bad sensors or loose wire.

Did you change the coolant recently?

An air pocket many be trapped on the top of the coolant sensor.

Try to locate a small air purge bolt near the coolant temp sensor.

If you can not find it then just back off the sensor and let some coolant to come out.

Please have container and shop towel to catch the coolant.

The goal is to purge the air pocket.

Please make sure it is level and engine is cold when you do this procedure.

Hi. Your Corvette is known to have gauge cluster issues. Have you tried unplugging the temp sensor and recheck the cluster. With it unplugged, key on, the cluster should read zero. You can also try unplugging both the sensor and the cluster. Then test the wire at the sensor. It should be open (no ground). if it passes then you may need a new gauge cluster. if so here is a name of a company that can help. Advanced Electronics Remanufacturing (AER)
Brea, CA 92821
800-321-6970
http://www.aertech.com

What diognostics say its a sensor ?????? No diagnostic's ever tell's you it's a sensor . You as a technician would need to prove that by testing electrical circuits , viewing coolant temp sensor . Hooking scan tool and trying to command the gauge with by directional control . The temp gauge not showing any temp. ? No movement ? Engine Coolant Temperature Gage Inaccurate or InoperativeStep Action
Yes
No
Schematic Reference: Instrument Cluster Schematics
1
Did you perform the Instrument Cluster Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - Instrument Cluster
2
Install a scan tool.
Turn the ignition ON, with the engine OFF.
With the scan tool, perform the Lamp and Gauge Check in the IPC Special Functions list.
Does the engine coolant temperature gage move up and down when commanded?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Replace the IPC. Refer to Instrument Cluster Replacement .
Did you complete the replacement?
Go to Step 4
--
4
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2
Would hate for you to replace the coolant temp sensor an find out that's not the problem ! Does the vehicle start an run good ,trans mission shift good ? If so it's not the coolant temp sensor .
Engine Coolant Temperature Gage
The ECM sends coolant temperature as determined by the coolant temperature sensor to the BCM via CAN serial data. The IPC displays the engine coolant temperature with the gage when the BCM sends a class 2 message to the IPC indicating coolant temperature percentage. The engine coolant temperature gage defaults to cold (0°) or below if:
• The ECM detects a malfunction in the engine coolant temperature sensor circuit.
• The IPC detects a loss of class 2 communications with the BCM.
• The BCM detects a loss of CAN communications with the ECM.

it is a sender unit not a sensor unit
take the wire off it and see if the gauge falls to zero
put the wire back on and if it goes to hot ,replace the sender unit
the difference is that temp gauge sender units have 1 wire to it and work through the gauge to it then through a heat altered resistor in it to earth (ground)
A temp sensor has more wires to it and works from the ecm
it closes a circuit when the coolant reaches a preset temperature, sending a signal to the ECM which then closes a relay to make the fan/s run to cool the radiator

check your coolant. the temp is the water temp. Your radiator is out of water? you`ll burn out your water pump. Also check to see if your radiator fans are running constantly.

You may two problems and one symptom. you may have a blend door problem that is not allowing air to circulate threw the heater core. also you may have a bad connection or weak coolant temp sensor showing you erratic readings and it may have nothing with the heat in the vehicle. you need to eliminate or separate the one of the the problems to diagnose your one symptom.

THERE ARE TWO TEMPERATURE SENSORS. ONE FOR THE ECU AND ONE FOR THE GAUGE. THE ONE FOR THE GAUGE IS USUALLY A SINGLE WIRE, EITHER WAY TRY REPLACING THE SECOND ONE.

Locate the temperature sending unit and pull the wire off of it. Turn the key to the on position (do not start) then have someone touch that wire to a ground source and the temp gauge should go from one extreme to another (cold to hot). If the gauge does that, you have a bad sending unit...if it does not move, you have a bad gauge or problem with the wiring to the gauge.

All the temp sending unit does is act like a variable resistor depending on the coolant temp...if it is bad, it will give you a false reading.

Unfortunately No, All of the Guages run straight into the Computer. If you bypass them you will have error codes out the Wazzu and lights on the Dash Constantly. Try a Salvage yard for a Replacement Guage Cluster.