A/c Fornt Blower not Working
07-23-2015, 09:53 PM
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A/c Fornt Blower not Working
My front blower recently quit working. The rear one works, but blows hot air from right side and cold air from left side. The code is FRA V 1426.
I've checked the blower...runs fine with 12 V. The controller delivers 9 v on the low setting and upwards of 12 volts at high setting.
Seems to be an issue with duo-valve on rear, but why does the front not blow?
6 most ago the front blower would not work at start-up until I hit a bump, then all was fine.
Any suggestions? I've checked the fuses, but it appears that one 40 amp fuse in the front hood area does;t even exist, so I might be looking at wrong fuse box....
I've checked the blower...runs fine with 12 V. The controller delivers 9 v on the low setting and upwards of 12 volts at high setting.
Seems to be an issue with duo-valve on rear, but why does the front not blow?
6 most ago the front blower would not work at start-up until I hit a bump, then all was fine.
Any suggestions? I've checked the fuses, but it appears that one 40 amp fuse in the front hood area does;t even exist, so I might be looking at wrong fuse box....
07-24-2015, 09:04 AM
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Good call. I did purchase a new blower, because the other one didn't really turn well at all voltage levels. Put all back together and nothing.
Could it be the controller? Since I haven't put on the cover yet, I can pull the wire from controller to the blower and check if the controller is managing the signal correctly...today.
If not that I'm leaning toward the climate control unit (yikes!)...anything I can check on the rear a/c (which is working OK- except for a right vent no cold air problem) that could interact with this front blower signal?
Could it be the controller? Since I haven't put on the cover yet, I can pull the wire from controller to the blower and check if the controller is managing the signal correctly...today.
If not that I'm leaning toward the climate control unit (yikes!)...anything I can check on the rear a/c (which is working OK- except for a right vent no cold air problem) that could interact with this front blower signal?
07-26-2015, 09:36 PM
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Quick update. Decided it was the controller (resistor) that has failed. I checked the local stealer-ship they want $395...FCP Groton -$105. Ordered it last Friday morning with next day air, but appears they are waiting until Monday to do anything. Pulled off the blower cover to expose the resistor device and took the two screws out to drop off resistor. I have jumped the controller/resistor with alligator clips from a/c climate unit across to blower inputs-with two thick wires-one with a built-in fuse and switch. I loaded a 40 amp fuse. Wallah! Instant blower on high when I activate and cold air. when the part arrives, I'll take off my contraption.
07-27-2015, 09:14 PM
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Final update. My part 551-321-1141 arrived today from FCP Groton. Looks a little different than the original (an extra prong that I'm not using), but Mercedes said this was the replacement part.
Took off my work around and installed the replacement part. A/C works fine ! The rear A/C also works better now. When the front blower was on-again-off-again, the rear A/C vents waffled between ice cold and damn hot. We'll see if this fixed everything (front and rear) or the duo-valve might cause that rear A/C vent issue again.
I did replace both the blower motor and the resistor (controller). Did this because either the controller was old and failed or the blower motor brushes possibly started to wear and strain the controller to end it's life early.
Took off my work around and installed the replacement part. A/C works fine ! The rear A/C also works better now. When the front blower was on-again-off-again, the rear A/C vents waffled between ice cold and damn hot. We'll see if this fixed everything (front and rear) or the duo-valve might cause that rear A/C vent issue again.
I did replace both the blower motor and the resistor (controller). Did this because either the controller was old and failed or the blower motor brushes possibly started to wear and strain the controller to end it's life early.
