hornetswarm

Read that entire thread. I have single fan. I think I have a bad computer. However the schematics say there is a pcm power relay....no idea the location though. Also. With a.c. on the high speed fan does not turn on. Wtf. Pull temp sensor and fan comes on. New temp sensor wires read good. Voltage is good. Temp says 185 on the live date but no low speed fan.

Ok, so changed the fan thermal resistor, no change. Voltage to fan is good, since it turns on with the ECT disconnected. It has to be the computer, but I don't know how, since the computer also turns on the high speed cooling fan.

Aircraft mechanic, with some tech knowledge. Bought a 1997 ford contour for my senior. Its a working project. However, the person before me, did not keep the car in order. People who misuse and don't do the routine PM, drive me nuts. They let problems fester until they become multiple problems, that mask others. Be patient as I might have some interesting problems that are over my experience level. All in all, I enjoy challenges. Thanks for listening.

Fix the short. Unplug Battery for five minutes, if you have a code reader, check for codes and post.

Check battery connections. Does the car turn over?. Maf disconnected will not normally cause car to not start.

Also replaced thermostat, coolant, spark plugs and wires, timing belt and tensioners, valve cover gaskets, pcv valve, egr solenoid. Fan will not come on unless ect sensor unplugged. The car idles ok, but when put in gear, the idle drops to 600 and surges. Drives great, just no fan with everything hooked up and rough idle while in gear. No codes. Unless I drive with ect unplugged, then I get p0118.

1997 FORD CONTOUR, 4 cylinder, 2.0, automatic. 1. With the coolant temp sensor unplugged the fan will come on. (high speed). Check engine light comes on with code = p0118. 2. With the coolant temp sensor plugged in the fan NEVER comes on. Car gets hot, but does not overheat. If I plug in while the fan is going from above step, the fan shuts off. 3. With the coolant temp sensor unplugged, the fan comes on, and if I remove the low speed fan relay, the fan goes from (high speed) to low speed. 4. A/C compressor will not turn on (not worried about this yet) 5. No other codes. 6. What I have done A. Replaced ECT temp sensor, coolant sender, high and low speed fan relay, slaved in a different ECM (part number was off a little). 7. With live data running on a OBD2 and the engine coolant temp sensor hooked up, the engine temp reads normal. 80 when start up, and then up to 185 under normal conditions. However, with the ECT sensor hooked up and reading 185, fan never comes on. 8. When I run a diagnostic on my OBD2, the fan turns on, but shuts off when the test is over. I have a schematic and all lines read pin to pin, except reading to the PCM relay....??? Not sure where this is at, but I would assume the PCM relay is good, since the fan operates on both high and low speed, with the ECT sensor unplugged and low cooling fan relay removed. This is stumping me.