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.
Hi
In my 2003 Focus (2.0L DOHC), the cooling fan resistor and plug look just like the pic. If this is bad will it keep the A/C from turning on? From my uunderstanding, if this is bad, the high speed fan will not turn on. Checjked AC and had to recharge, and now when turned on the A/C will short cycle and no high speed fans. Checked all the relays and power feeds at the fuse box andall are good
Thanks
As far as I know it is just called a resistor assembly. I did look through my records though and found the Ford part number, F5RZ8L603AC. At least that was the number in Oct of 2009.
I see everything but the actual name for the resistor… I have typed it in and cant find it anywhere.. does it have an alternate name?
There are a lot of things that have to be considered in your case. The first thing is determining if the engine is actually running hot or is it a gauge issue. Has anyone driven the car with a scan tool connected and observed coolant temperature through the eyes of the computer system? Has anyone checked the engine temperature with an infrared heat gun?
If your air dam was missing or damaged it would have been very important to install a new one as it prevents all of the highway air from sliding under the care and bypassing the cooling system. the air dam is there to divert some of that air into the condenser and radiator.
The lower fan speed is important as it keeps the engine temp lower under less stressful conditions.
If it is actually overheating and the high speed fan is on most of the time you probably have a coolant system issue.
If it is truly overheating related to coolant and not electrical faults, a couple of thing come to mind. Damaged water pump impeller and missing thermostat.
I have a problem with overheating that neither my regular mechanic nor the dealer can figure out (though I don’t give the dealer much credit b/c most of their feedback was useless but of course expensive). So far I’ve replaced the thermostat, hoses, and radiator, air dam (thanks to the brilliant dealer), not to mention numberous flushes by this point. Nothing helped.
The car runs hot when I’m on the freeway for about 15-20 minutes. When I slow to exit the temp moves up a notch and will hover hot until I speed up and then it temporarily goes back down a bit. At 30-40 it will gradually cool a bit, but still not go back to normal. The circulation seems ok (also seemed ok to the mechanic) and the (high speed?) fan is running (sounds like in the summer when stuck in traffic with the AC on).
Do the other speeds matter differently than the high speed? If the high speed fan is on why wouldn’t that do an even better job than the lower speed? It would be fantastic if I could determine whether this might be the source of this annoying problem.