HVAC Air Issue

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Necrosan

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Hi,

To preface things: I have had a broken blend door for a while now, but I don't think this is related.

My blower motor cable that went to the module had failed (typical, actually melted the connector over time.) and required a bit of wiggling to make it turn the motor on.

So I bought the cable & finally got around to replacing it yesterday, and now the motor turns on and off when expected.

However, the air no longer makes it up to the vents (floor, upper vents or defrost).

Anyone have a clue what I may have broke replacing a simple cable, or is there something that may need to be reset because I unplugged it?

To be clear - the motor SEEMS like it turns on full speed now, but there is no air at all that makes it to any vent. It sounds like it is getting trapped somewhere near the blower motor itself.

Thanks!
 
slowmkviii said:
Did you wire the motor in backwards
Check all vacuum lines
Click to expand...

Impossible to wire it in backwards - it only can be attached one way.

I don't see anything obviously wrong with the vacuum lines, although the only ones I see are directly behind the glove compartment when you drop it.

Another note: Air blew perfectly fine out of the vents before I swapped the cable over. Are there any vacuum lines actually near the Blower Control Module/Blower Motor that I could have messed up?

Does the Blower Control Module control anything besides blower motor speed?

Didn't mention it in first post but it is a 98.
 
Even with no vacuum at all, it'll default to defrost. No way for all the doors to completely block the flow of air no matter how screwed up the climate control is. Not sure what you mean by "cable", but if it's a new wiring harness, you had to solder it in, right? I'm with slowmkviii, most likely the polarity is backwards.
 
Marcus said:
Even with no vacuum at all, it'll default to defrost. No way for all the doors to completely block the flow of air no matter how screwed up the climate control is. Not sure what you mean by "cable", but if it's a new wiring harness, you had to solder it in, right? I'm with slowmkviii, most likely the polarity is backwards.
Click to expand...

P7280004-1 (Small).jpg

By "cable" I mean the "wire harness" that goes between the blower motor & blower control module.
In the picture above, it has the orange/black thicker-gauge wires.
It only can be attached one way.

P7280004-1 (Small).jpg
 
Make sure to check the back of the EATC unit itself to see if the lines are all in their connectors, directly on the back. There is also another vacuum line that goes into a canister and it's mounted up inside the passenger side fender but it should be fine.
 
Do dismiss polarity its an easy check
I had a town car that was going the wrong way.
Not saying its the only possibility.
 
Seems l was wrong and a small amount of air is making it through the vents. Starting to think the blower motor is not operating at full speed.

Only possibility now is the blower motor control module as far as I can see. Going to futz with it a bit and see what happens. (For what it's worth, the burned end of the wiring harness was plugged into the module.)
 
Necrosan said:
Seems l was wrong and a small amount of air is making it through the vents. Starting to think the blower motor is not operating at full speed.

Only possibility now is the blower motor control module as far as I can see. Going to futz with it a bit and see what happens. (For what it's worth, the burned end of the wiring harness was plugged into the module.)
Click to expand...

Guess that wasn't the only possibility - tossed a known good working one in and get the exact same issues.
Now I'm leaning towards the blower motor itself unless anyone has any suggestions..
 
slowmkviii said:
Did you wire the motor in backwards
Check all vacuum lines
Click to expand...

After going crazy all day with this I did a bit of digging to see how Myco solved his problem and FINALLY found this post:

http://www.lincolnvscadillac.com/fo...get-this-Interesting-intermittent-a-c-blowing

I checked the cable vs the old one and sure enough, on the blower motor side of it the wires were reversed.
Swapped them around and the system works like a top again.

Really weird that the cable wasn't correct as I had the stealership dig up the part number for the Mark & they assured me it was fine.

Thanks again for all your help. (And congrats on hitting the nail on the head slowmkviii ;))
 
Below is a picture of the damage that occurred to the original connector that attached to the blower motor control module:

fucked_connector.jpg

My connection issue seemed to originate back there, not on the blower motor side like many others who encounter this common problem.

(FYI: The connector on the blower motor control module was also burned, so I replaced it with one from a 2001 Mercury Sable just to be safe.)

Also below is a cross reference guide for compatible blower motor control modules with the 97/98 Mark VIII:

FORD TAURUS (1996 - 2007)
LINCOLN CONTINENTAL (1996 - 2002)
LINCOLN MARK VIII (1997 - 1998)
MERCURY SABLE (1996 - 2005)

All of these should work fine as a direct replacement for the 97/98 Mark VIII.

fucked_connector.jpg
 
I know the panther guys (including my self) have allot of issues with the blower motor plugs burning up. There is a fix for it some where on Crownvic.net
 
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