1G Coolant Temp Sensor Problem

[ChvyKc]

I finally got the car out of the garage again after swapping the shocks/struts and putting the FP2's in but now I have another problem. My coolant temp gauge stopped working. The harness that goes into the sending unit has only had one wire in it since I bought the car and it has always worked fine. The other wire has always been disconnected from the harness and just hanging there, but when I plugged it back up after doing the cam swap the gauge has stopped working.

I tried cutting the harness off and putting terminals on both of the wires and plugging them in like they are suppose to but that didn't help. I made sure that the terminals were not touching so they would short the connection out and I couldn't get the gauge to move at all. The logger was reading negative 15 degress also so the ECU is just not getting any kind of signal for the sending unit.

I have also just put in a new coolant temp sensor and it didn't fix the problem. The coolant temp sensor is not a factory one so the terminals on it are a little different. They don't go the same way but I have tried the wires one way and the other and the gauge is still not working. The logger is picking up a bad coolant temp sensor code also. I can clear the code and start the car back up and the code will just come right back after about a minute of run time. I just wanted to see if there is anyway that I can test to see exactly what is wrong. I need to get this problem fixed so I can get the car on the road and tuned. Any suggestions?

 

[Talesin]

Your temp gauge and coolant temp sensor code are two different problems, as they use two different sensors.

The gauge cluster is a single wire spade connector, closest to the front of the engine on the thermostat housing. My mechanic had snapped the wire off... just recrimped the spade connector, slipped it on, good to go.
The coolant temp sensor is just to the left of the gauge cluster temp sensor, and is two wires, and should have both hooked up to work properly. I'd pull the connector and look at it, make sure the wires are crimped solid and in good shape.

Can't think of why they'd need to, but it sounds like they pulled off your IC piping and were playing with something down inside... my problems came from the mechanic forgetting to unhook the harness during a starter swap, and snagging/pulling wires off of the connectors accidentally.

 

[ChvyKc]

No, we didn't take the intercooler piping off. I did the cam install myself. I don't let any mechanic touch my car unless it is just something that I can not accomplish myself. I have had bad experiences with shops around here in the past.

That explains a lot. Thanks for the suggestions. I thought that the gauge in the cluster worked off the sensor in the top of the water neck that was a two wire sensor. I will have to check the other one out and see what is going on with it.