2008 Overheating- Radiator fan not coming on

[KDreyer523]

2008 non turbo. Brother gave it to me because it needed a timing belt. Fixed that, but now have many other issues. Worst issue right now is the overheating.

Radiator fan and relays are new. Also checked them on another cruiser and they worked fine. Radiator fan and relays are not the issue.

Swapped TIPM with a similar cruiser that had no fan issues, still didn't work.

Checked voltages on radiator wiring harness. Getting 12 volts power and ground is good. Getting nothing on low or high speed relays (again, at the harness). Made sure ac was on when I checked so low speed should have been getting something, right?

Car temp gets hot quick so coolant temp sensor is working. Maybe?

AC does not blow cold, but I hear the compressor clicking on and off. Replaced the low pressure switch and tried the paper clip trick with the high pressure switch harness, but nothing changed. It sat for awhile so condenser is probably bad. Will try and check AC pressures next, and if they aren't good will put a vacuum on the system and see how long it lasts. Just couldn't get my gauge on the high side port today.

Pretty sure both the high and low speed wires to the harness would not have shorts, but not sure how to test them.

Really need this car but have wasted a lot of time trying to solve this issue. I'm guessing either PCM, high pressure switch( maybe I didn't test it right) or there is just a wiring issue. Any thoughts?

[alanrw]

Don't guess. Get a DRB III tool on it. You can get into a submenu that will turn the fans on low and high. At that point, you know the wiring, fans and relays are good.

[KDreyer523]

Sounds like an excellent tool, but is there an affordable version. Most I see run into the thousands.

[ptcruisersteve]

I would still suggest checking the engine coolant temperature sensor. Its possible you have two problems (with the A/C high pressure not kicking in) and the ECT not sending the signal to the PCM to turn on radiator fan. If both are down then the radiator fan does not come on at high or low speeds with or without the A/C on.

Its possible for the PCM to have a failed relay driver causing it not to signal the TIPM but this is very rare. Usually if the PCM had this problem it would have other problems showing also.

[JoeX]

Check the fan harness connector for heat damage around the pins,
keep in mind these fans last about 100,000 miles and may work intermittently just before complete failure.
I had my new one out 3 times before I noticed heat damage around the ground pin which causes both speeds to not work.

[KDreyer523]

Changed coolant temp sensor today and finally heard that magical sound of the fan turning on. Put a charge on the AC and now it is blowing cold( bonus). Took me almost a half an hour to change it today. Would have taken 30 seconds when I did timing belt. Lesson learned. Thanks for all the help.