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[FIXED] 2006 Freestar 4.2L engine cooling fan#2 not workin
I have this van that at first had no AC, which upon further looking I found that neither of the engine fans were coming on at all, so that was a good reason for no AC..lol. I attempted to engage the fans thru an old Genysis scan tool I had handy but could find no bi directional functions. Next day, used our laptop based Auto Enginuity scanner and although it had listed actuations for the fan relay, I got an error of the test was not supported by the vehicle..fine, I go and was able to manually with my power probe at the fan relay box, have both fan fire up. I noticed alot of green corrosion on many of the wires coming into the bottom of the relay box, so I unsuccessfully attempted to pull each wire out to clean it and had to settle for using some tiny contact cleaners we have to clean up the female receptacles contacts. That brought back fan #1's function, but no luck with #2, so now the AC works kinda ok at idle but of course works great once you start driving.
Question is, since I can't use the scanner to turn on the fans, how do I test to see if the PCM is actually calling for fan #2? From the diagrams I have, I am thinking the PCM is controlling the grounds to the fans. Should I scope the pin for cooling fan control at the PCM to see if its grounding properly?
Thanks for uploading the wiring diagrams with your post, makes it super easy to follow along. Are there seriously five relays, for two cooling fans? What a goofy setup :blink:
You're right on about the relays being ground side controlled by the PCM. Scoping all the relay control pins would work, but it might be faster to just use a test light connected to B+ instead. This will load the circuit and help expose any other wiring issues present.
Looking at the diagram, the control for the #2 fan is tricky. Power comes from relay #2, simple enough. Ground can be found several different ways, involving a fan circuit breaker, fan #1, relay #5, and a dropping resistor... I think this is all so the fans can be run individually at different speeds? Did I mention this is a goofy setup?
Anyway, if it's easily accessible, it might be faster to check for power and ground at fan #2 directly, and follow which one you're missing. The dropping resistor and the circuit breaker are high on my personal list of suspects.
What is with the signal low, serres dual low, parallel dual high control staging. That is a bit off the deep end for control, that is asking for trouble. This is what I get from the diagrams and my theory on operations
1 on= single low (above thermostat control or below with a/cl)
2, 4, 5 on= serres dual low (above thermostat control with a/c)
1. 2, 3, 4, 5 on= parallel dual high (over heat state with i expect a/c cutoff)
Haven't forgotten the thread guys, just haven't had the van back in the shop yet to continue this investigation. First thing will do is trace back the power and ground from fan 2, like Tyler suggested. Appreciate the input guys!
Update: I repaired the problem. It turned out to be a wire running from one of the relays to another, the wire was all corroded with green death. I just touched it and it popped loose, so hadn't really been making a connection. I had been attempting to use the alldata diagrams I had and sorting thru the circuit, turns out the wire colors were not the same, but no matter, once I repaired this wire and cleaned up all the other crud I could see, the fans worked perfectly and A/C of course was back to normal at idle now that it had some air flow over the condenser!
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