2003 Ford Focus, Runs Hot, Cooling Fans Inop, Part 2

Welcome to part 2 of this repair on the cooling fan system on a 2003 Ford Focus. To see part 1 please click here.

I consulted the wiring diagrams further and found that there was a fan resistor located in the fan housing. After unplugging the connector this is what I found. One terminal was badly damaged on the harness connector.

The resistor was damaged as well.

I spliced in a new harness connector. The connector part numbers are Ford#4U2Z-14S411-DA Motorcraft# WPT822, The Electric Connection #4071

Installed a new resistor.

Hooked the connector to the resistor.

Retested the system and all is well. My guess is that the resistor and its connector were the original problem and poor test methods by the previous shop had pushed the terminal for the relay out of position.

31 discussions on “2003 Ford Focus, Runs Hot, Cooling Fans Inop, Part 2”

  1. Hello,
    I have an 02 Focus which has the same issue. The harness plug is fried and the resistor prob needs changing as well.
    Where did you get the harness plug and resistor?
    Thanks for any help.

  2. Is your Focus overheating? The engine temperature has to get quite high to turn the fans on without the a/c. Is the gauge reading high or is it boiling over? To get into the computer system you will need the use of a good scan tool that reads data and preferably on that has bidirectional controls.

  3. Hi,
    I have same problem. When I turn on AC fans are working but Other way they are not. I changed resistor pack, relay and Engine Temp sens but Fans are not working. What is my foci’s problem? How can i check with computer system?

  4. The relays and resistors in the post that I did were only for the cooling fans. You seem to have a blower motor issue and the resistor for that system is under the passenger side of the dash near the blower motor.

  5. Hey Sparky,

    I’m having problems with my fans turning on, too. Originally, I thought the fans were the reason why my car was overheating. Well, what I discovered was that the thermostat housing was leaking, which is apparently a fairly common problem with Ford Focuses. Anyway, so I fixed that and also replaced the thermostat while I was at it. The good news is that my car isn’t overheating anymore, but my fans still aren’t kicking on at all.

    I have a 2002 Focus, and now the fans to circulate air in the cabin won’t kick on unless I set the fan to the highest setting, which is 4. Also, the A/C and heat won’t come on unless I put it at 4. Do you think I should just check the resistor near the fan box like you did and replace it? Or, do you think I should check that out as well as all of the fuses and relays involved with the A/C, and fan systems?

    One more thing, I was looking at your photos from the work you did on this ’03 Focus and I noticed that the relays you were working on were in the R9 and R10 positions. Yet, in my owner’s manual I noticed that those positions were listed as “Not used”, and that the two relay positions for the high and low speed fan were in positions R15 and R16. Any idea what that’s all about or should I just go by where the relays are actually located in my pwr dist box and not according to the manual? I haven’t checked where they’re at on my car yet, I’m gonna do that when I work on this. Maybe the relay positions were just switched for the fans from the positions in the ’02 model to the ’03.

    Sorry about the long post, let me know what you think. I appreciate your time. 🙂

    -Steve

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