eatc issues

[jagbucket]

Newbe here but still an old guy.
i started out buying a jy 99 5.0 motor for my bronco project and the next thing i know after an $800 exchange another 2000 mountaineer/5.0 just followed me home has 205 thou. and still runs great no noises or leaks I think this last generation of the 5.0 is bullet proof. Same cannot be said for the eatc heating system. it has the run in high only fault. i have read all the posts i can find and have replaced the speed controller with a new one , replaced the fan motor with a lower mileage one with no luck .
I just found the post with the tests from the service manual that i will attempt tomorrow.. failing that how can the interior controller be tested?
The steering control does the same thing hi only, so if both interior inputs have the same problem does that point back to the new speed control ?

So far ive replaced a fender, door, front bumper headlite ass. grill and header panel the best part is all in the correct original color there's alot of these around so parts were cheap. no frame damage just bolt and go except for these electrical issues that the po just lived with ..

 

[koda2000]

usually this problem is caused by a bad fan control module or a dirty/corroded connector at the controller. as you say you're replaced the control module (i'm assuming with a new one) i think the problem may be in either the steering wheel switch or the EATC fan speed switch. try running the EATC diagnostics, but if that doesn't find a problem try disconnecting the steering wheel switch and see if that helps.

 

[jagbucket]

i ran the self test several times and finally got it to work result was all okay 888 i will try the disconnect as you suggested although it does work in the hi setting same as the dash control if the speed is lowered fan quits dash and steering. i found two different tests online but they are useless without the pin layout numbers and less than clear directions on whether or not the plugs are installed or disconnected and which unit is being tested as they do not call the parts by the same name each time. the eatc unit does seem to work in all functions except lower than hi fan running.

 

[radman]

Same Fan Speed Issue

My 99 Eddie had the same exact symptoms as you describe, everything in the EATC system worked except fan speed defaulted to high speed and if a lower speed was selected it would not run at all. Both the dash and steering wheel controls did the same.

This is a common problem. Using the advice posted here the Fan Speed Control Module was replaced with a new Motorcraft unit from Rock Auto Parts. No more problem.

You did not specify where your replacement came from you might want to try another module.
Mike

 

[jagbucket]

yeah i got it from napa $92 i know i could have gotten it cheaper but was impatient and thought that was the issue.
today i got the loan of two eatc units from navigators thinking i could at lest trade fan wheels but the plugs on the circuit boards are different. the rear plugs are the same so i'm tempted to try one just to see if the fan works trouble is the navigator has outside temp where the explorer has rear fan off button. IDK

 

[jagbucket]

to update; the navigator eatc did not work at all ,,
i finally paid to have the question answered and received 108 page copy of fords service manual on the ac/heater system. the part that i needed for the fan problem was about seven pages. The result is after running through preliminary tests for shorts, continuity and voltages the last test determines eatc or controller, on the blk plug for the eatc near the center there is a pk/wht wire should have battery voltage when on hi fan, for lower speeds an or/brn wire next to it separated by the lock tab should have voltage if not its the eatc if it does its the speed controller.
tomorrow i will try the only jy around that said they had the correct eatc but wants 65 for one

 

[jagbucket]

replaced eatc unit and all is well. only thing left to repair is the sunroof which can wait until spring if then. so far door locks, windows, overhead console, radio display and now the fan have been repaired on top of the body damage but with 205K i guess that's normal just that the po never fixed them.he did try to seal the radiator with undercoating so maybe i'm better off that he did not.

If anyone wants a copy of the factory steps to troubleshoot the fan pm and i can send as a email

 

[jagbucket]

Fan working on hi again but this time it works on hi all the time no matter where the switch is placed as the original problem was only running when on hi, that turned out to be the eatc computer now the new speed controller i installed but didn't need, has quit so that it runs hi always. Put the original speed controller back in and it works correctly, parts store will not give back the $92 but will replace the part. only lasted for a week so when i get the new one I'll install it to test before it gets to old for another return

 

[shadowless127]

it's the fan speed control module. common issue.

 

[jagbucket]

Yes its a common issue and that's why i went ahead and bought a new one only to find that it was not the problem but the eatc unit, which i also replaced, while i thought i was done with it, a week later the new speed controller quit. my point in posting was to show how the system acted when either one was defective as i experienced both and that is;
fan runs hi speed no matter the interior setting = speed controller under hood .

fan runs hi speed only when interior request is on hi and quits at all other settings = eatc unit