Temp Gauge

I recently purchased a '91 4.3L S-10 w/ 65K mi. The previous owner took it to the dealer once because the temp guage reads hot as soon as you start it. they didn't fix it and he never drove it so they left it. I have replaced the thermostat and sending unit I also flushed the cooling system. The sending unit was cracked but it didn't fix it. When you unplug the wires from the sending unit the temp guage goes down. The dealer wasn't very helpful, he said there are 2 sending units but wouldn't walk outside to show me. Any Ideas?
Thanks
Beau

I recently purchased a '91 4.3L S-10 w/ 65K mi. The previous owner took it to the dealer once because the temp guage reads hot as soon as you start it. they didn't fix it and he never drove it so they left it. I have replaced the thermostat and sending unit I also flushed the cooling system. The sending unit was cracked but it didn't fix it. When you unplug the wires from the sending unit the temp guage goes down. The dealer wasn't very helpful, he said there are 2 sending units but wouldn't walk outside to show me. Any Ideas?
Thanks
Beau


I have a 92 and am trying to find where the temp switch is located. I think that the temp switch runs the Meter on the dash. The other one is used by the ECU. I have no idea why they are named the way they are. It seems a little silly.

the ECM sending unit is the one next to the thermostat housing.

the temp gauge sending unit is between the number 2 and 4 cylinders on the passenger side of the motor