this in an ongoing problem for me. my fans will not work without the a/c on. the resistor and wiring was replaced a few months ago. no change. fans still only work when a/c is on. is there an accurate way to test this resistor? thanks.
Can you monitor your engine temp using the electronic odometer test mode? The directions are detailed in the How-To archive in the dark blue banner just below the title of this thread. Engine temp will be displayed as [89 C], and will be displayed in Celsius.
I have done that. I get a steady climb to 110 C and still no fans. I then turn on the a/c and it slowly cools down. I don't like getting my hoses this hot very often. Because of obvious reasons. I am wondering if there is a way to remove and test the resistor. thanks.
You can test a resistor that is part of electronic system using a multimeter, I'm sure it would apply in this situation too if you can find the specs. Honestly so many of these have been documented to fail that probably its easier to buy a new one. It takes 1 minute and no tools to remove the old resistor and put in a new one. If the wiring harness is burnt out that could be it too. In my case with my 02 I had to replace both parts.
With a multimeter, Ford specs say you should see a resistance of 0.25 ohms between pin 1 and 2 of the resistor. I assume if your fans don't work and the resistor alone was faulty, you'd see an open or infinite resistance.
But as DeeZX5 points out a bad resistor usually takes the wiring connector and some wiring with it.