99 Windstar rear blower inoperative

Spools · 07-10-2005, 09:28 PM

My rear blower motor does not run irrespective of switch positions of either front or rear controls. The rear two relays click along with the fan speed switch positions (have swapped these between each other to try to change sysmptoms - did not change anything). Found rust on contacts of blower resistor (thing that mounts to the housing assembly - cleaned contacts to no avail. Internal side of this item is very rust all over). Have 12VDC on each of 2 leads going to blower motor when fan switches are on. Blower motor measure low ohmage (1-8 ohms). Any suggestions? What is reasonable resistance reading for this motor?

dougand3 · 07-11-2005, 06:54 AM

Welcome to the forum, Spools.

I don't know what the ohms should be. Can you get the motor out w/o pulling the whole AC/Heat unit? If so, I'd take it to a parts store and have them pull a similar spec motor...then compare the resistances. If you can't pull motor...maybe compare to, say, a radiator fan motor?

12Ounce · 07-11-2005, 07:32 AM

The OG/RD wire from the motor is the one that normally goes to ground path ... through the relays and then through the resistor block.

I suspect the resistor block is "open" ... or its BK wire is not grounded as it should be.

Spools · 07-11-2005, 11:01 AM

Thanks to you both for the quick replies. I now have the motor out of the van- it turns freely. I can see one of the bushing on the amature - things look reasonable. Do Part Stores allow folks to measure their stocked items?
While everything was intact, I unscrewed the resistor pack where I was able to view the "guts". Things were rusty but all pieces appeared to have continuity (2 coil-type resistors, a jumper wire, and a diode(?)). I measured each leg of each component of the resistor pack to ground. For each leg, I measured 12VDC relative to frame ground when the fan speed position was in any of the on positions. They all went to zero with the fan switch put to off.
I tried to find the part #s for the resistor pack or the motor at one of the part store web sites but have been unable to find the correct parts. I was looking for estimated prices for each. If the resistor pack is inexpensive, I'll take a shot at that 1st. Thoughts?
Thanks

12Ounce · 07-11-2005, 01:19 PM

I'm assuming the resistor pack has three "legs" (terminals). And on one of them is a black conductor. The black conductor should never be at 12v ... no matter which position the switch is in ... as it should be connected to a solid ground.

Everything else you describe is as it should be. Look for a problem in the black wiring.

Spools · 07-12-2005, 07:55 PM

12Ounce, Dougand3 - thank you for your advice. My problem is resolved! I changed the Resistor Assembly (p/n 4F2Z*19A706*BA, $12.00 from my local Ford dealer). The fan is working fine - just in time to take the family on vacation! Thanks

12Ounce · 07-12-2005, 09:41 PM

Good work!

Before you close the panel up, you may want to consider disconnecting the elect connector going to the "mode" (ceiling/floor) door actuator. I find my rear ac unit less disturbing to the the driver if everything from the rear ac unit comes only from the ceiling vents.

It's a matter of personal choice, of course.

dougand3 · 07-13-2005, 09:20 AM

Good you got it working.

"Do Part Stores allow folks to measure their stocked items?" My local autozone does...recently had rough running...checking everything...with the coil pack - I checked the pri and sec resistances and went to az with a multimeter...they pulled the replacement and I checked it and compared....mine was within tolerances...so I didn't buy a $75 part. I'll go to great lengths not to buy a new part - LOL.

5greenmonkies · 08-03-2008, 09:58 AM

Quote:

Originally Posted by Spools

12Ounce, Dougand3 - thank you for your advice. My problem is resolved! I changed the Resistor Assembly (p/n 4F2Z*19A706*BA, $12.00 from my local Ford dealer). The fan is working fine - just in time to take the family on vacation! Thanks

I have the same problem with my 2001 Windstar. I didn't understand all of the troubleshooting dialogue (way too advanced for me) but I'm wondering how difficult it is to change out this Resistor Assembly. I had other rear a/c problems last year so I know how to get to the rear blower motor but need the steps to replace this Assembly.

Thanks in advance

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