Problem with blower

[bgarib]

Hi everyone, so I've read tons of threads on blower motor problems. My 2000 Ford Explorer Limited is having issues with the blower. I have the automatic environment control thingy. It stopped working one day. When driving on the highway I still get some heat radiating out of the vents, but the blower for sure wasn't working. Here's what I have:

1) Took the blower motor out, tested it against the battery. It barely turned and smoked a little. Tested a new blower motor, works great when connected to the battery.

2) Checked the fuse by the driver's door. A-OK

3) Checked continuity with the relay. Got the beep, looks good.

4) Checked continuity with the plug that goes into the blower motor. Got the beep, looks OK.

5) Checked voltage that the plug. I get -8 to -13 (depends on the fan setting). I only get that when I put the red diode to the orange/black cable, and the black diode to the pink one. All other combinations, including ground to the car, don't work.

So, the blower motor still doesn't kick on. Is this the blower motor resistor probably? Is there another switch in between the resistor and relay that might be the problem? HELP!

-Brian

 

[bobflood]

The EATC units have a "fan controller" instead of a "blower motor resistor" - in the same place and does the same thing - just a lot more expensive. Thought you don't state it, I assume you have the new blower motor in and it doesn't work? Check to make sure that all your related fuses are still good. Good luck.

 

[bgarib]

bobflood, yes, I do have the new blower motor in and it doesn't work. Well, more like I'm testing it and plugging it in before it's really formally installed.

Is there another fuse besides the one in the fuse panel by the driver's side door?

 

[J_C]

You should be able to probe with a multimeter to find out if the EATC is bad or not by determining whether, while the blower should've been on, there is power getting to the plug for it. Probe between any chassis ground point and every pin to see if there's power getting to it, a voltage reading and what that reading is.

If there isn't, there's a fuse, relay or wire fault before it. If there is, but not going out to the blower, then the EATC itself is bad. Personally if it is the EATC and considering its expense, I'd try to repair it instead of replacing it. It could be as simple as a broken solder joint or excessive gunk buildup on the connector contacts that needs cleaned off, or a subcomponent failure like the main transistor.

From other topics about it, it looks like the main issue is just having a high enough wattage iron to melt the large amount of solder they used. If replacing the transistor, be sure to clean the mating area on the heatsink (scrubbing with steel wool might help) and use a fresh coating of thermal interface, heatsink grease.

http://www.lincolnforums.com/forums/threads/6966-Cheap-fix-for-EATC-blower-speed-controller

If it does turn out to be the module and you need further assistance with its repair, post links to some high resolution top down and bottom up pictures of it.

More info that might be related,
http://www.idmsvcs.com/2vmod/eatcswap/blowercontroller.html
http://www.explorerforum.com/forums/showthread.php?t=384469

 

[RomeovilleIL]

From your testing I would lean to the blower motor control. Thats a part that really should not be pulled used as they tend to all be wearing out at this point. A new one aint cheap - $70 to $100 depending on aftermarket or dealer. I would imagine you could jumper the control module plug, though would only give you full power at the blower. If memory serves, the two thicker wires are a main power in that should be hot in start (verify with your mulitmeter) and power out to the blower motor. The smaller wires are the inputs from the EATC. If you jump the larger main lines with a piece of wire and two spade ends that should give you full power to the motor and verify there isnt a broken wire or short somewhere else. Would allow you to run heat, albeit only on high speed, until you get the replacement part though might want to throw an in-line fuse into just to be safe if you think it might be a while on the part.

 

[bgarib]

Alright, thanks everyone for the info and details. I get everything working, here's a summary.

I retested the blower motor relay and got the beeps at two different slots when testing, so that confirmed power to there was good. I wasn't really able to confirm anything at the plug to the resistor, I don't think my multimeter could connect to it and I couldn't get voltage.

I ordered a blower motor resistor from Rockauto, installed it, and all is good everything works, woo hoo! It turns out that the bad blower motor also blew the blower motor resistor which I hear is common. Man, the screws on the resistor are super hard to get at. Thanks everyone.