Does anyone have a good pic or diagram of where the thermostat ground begins, and ends. This is for an 89 civic lx, i tried searching and all the post contain dead pics. thanks.

 

Trace your lower radiator hose back to where it connects to the engine. Right above that should be a few wires that are bolted above the waterneck. This is your 'thermostat ground.'

 

Now where does it start? I have a torn up Z6 harness I will start tracing for you.

 

It doesn't matter where it starts. Just run a new 10-12 guage wire from the thermostat housing to chassis ground. To check your current connection, measure the resistance of the point to chassis ground. It should be fairly small. If you can confirm its not a good ground, then run the new wire.

 

the ground wire that connects to the thermostat housing does not ground the thermostat housing to the chassis - this ground wire comes out of the engine harness and connects to the thermostat housing and is the ground wire for the ECU, Main Relay, O2 sensor, Coolant Temp Switch, Top Dead Center Sensor, Cylinder Position Sensor and Crank Angle Sensor - the ECU and Main Relay grounds come from ECU pins A2 and A4 - the O2 sensor, TDC sensor, CP sensor and Crank Angle sensor grounds all come from ECU pins A16 and A18 - the Coolant Temp switch ground does not go to the ECU, just directly to this ground wire

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jlicrx &raquo;</TD></TR><TR><TD CLASS="quote">the ground wire that connects to the thermostat housing does not ground the thermostat housing to the chassis - this ground wire comes out of the engine harness and connects to the thermostat housing and is the ground wire for the ECU, Main Relay, O2 sensor, Coolant Temp Switch, Top Dead Center Sensor, Cylinder Position Sensor and Crank Angle Sensor - the ECU and Main Relay grounds come from ECU pins A2 and A4 - the O2 sensor, TDC sensor, CP sensor and Crank Angle sensor grounds all come from ECU pins A16 and A18 - the Coolant Temp switch ground does not go to the ECU, just directly to this ground wire </TD></TR></TABLE>

edit: i got it. thx