Cooling fan stays on

My driverside cooling fan comes on when the key is turned on and runs all the time. I ran KOEO codes and got 83. My question is where do I start trying to troubleshoot this problem. Is it the ECT or IRCM. It just started doing this just recently. Any help would be greatly appreciated.

Dom

One source I have says the code 83 means: "2.3 Turbo only. Check EDF signal to Integrated Controller for open circuit."


Here is an article on fan diagnosis, although I don't think it speaks to this condition. The wiring colors mentioned may help.

Here is an article on the IRCM. It may help if the relay is determined to be the problem and you want to replace it your self.
http://www.turbotbird.com/techinfo/New_IRCM/IRCM.html

Thanks Pete, I will have to check the inputs and outputs of the IRCM to check for a cicuit failure. If I am correct, doesent the ECT send a signal to the EEC and it activtes the relay in the IRCM to activate the fan? My fan started doing this after a trip of about 200 miles to Oklahoma and back. I guess I wont have to worry about overheating this summer!! LOL

My website has the troubleshooting steps that Ford's dealerships use:
http://www.tbirdheritage.com/turbocoupe/...-Chart.php

Code 83 is there:
http://www.tbirdheritage.com/turbocoupe/...stepid=X30

Don't really need a breakout box. It just simplifies things. You need to focus on the wiring between the EEC and IRCM. If that checks out, then it's either one faulty.

I checked the article that Pete D links and I don't think, in my small opinion, it really address what is happening in this issue.

You are correct that the ECT provides the EEC with engine temperature information that is used, among other things, to control the cooling fans.

Basically, the primary fan runs when the EEC ungrounds the Tan/Orange wire at the IRCM. This means that the EEC must ground the Tan/Orange wire at the IRCM whenever the primary fan should NOT be on. This is considered a "failsafe" in case there is a "communication" issue between the EEC and IRCM. If there is a "communication" issue between the EEC and IRCM, the primary fan will constantly run. This is what you have. The secondary fan operates in the opposite way.

So, in your case, there may be a "communication" issue between the EEC and IRCM, thus, the IRCM is commanding the primary cooling fan to operate. Or, it's possible (but somewhat rare) that there is no "communication" issue between the EEC and the IRCM, but the EEC is simply not grounding the Tan/Orange wire at the IRCM. In that case, the EEC would be faulty. It's also possible the IRCM itself is faulty.

Given you received code 83, you can (at this time) rule at an ECT issue because code 83 indicates a "communication" issue between the IRCM and EEC and the ECT is not involved in this case.

Good stuff and thanks JT. I guess I will get under there and start checking wiring first, then signals and IRCM. Your input is a great help.