Blower Motor/Fan Speed Varies

[WhatsUpDOHC]

Hi -

Another question for the experts:

When my A/C or fan are on, the blower varies in speed.

Fast, medium, slow and all variations - Won't maintain the same speed.

Is this a common issue with the MM/Panther (I hadn't experienced it with my '98 CV)?

Thanks!

Mark

[RF Overlord]

Is this a common issue with the MMNo. Yours is the first I've heard...

[WhatsUpDOHC]

No. Yours is the first I've heard...


Greeeeeeaaaaaat.

Been there - Glad that I have a warranty (and haven't done any mods).

Mark

[fastblackmerc]

If the EATC is set to AUTO, the fan will vary in speed.

[WhatsUpDOHC]

If the EATC is set to AUTO, the fan will vary in speed.

I never allow the car (as much as I love her) to take control.......

No Automatic Temp control - All manual controls of temp and fan speed.

Mark

[B.C. Bake]

Ok, this one takes the cake and made me :rofl: moving on ........:lol:

[B.C. Bake]

Ok, this one takes the cake and made me :rofl: moving on ........:lol:

Ahhh..Ohhhh...for some reason I was thinking fan speed being the radiator fan :rolleyes:."made me lol though". But now thinking about it, check out the battery or the alternator output volts when the compressor kicks on could be a low voltage condition causing everything to dim or slow down for a moment. Now moving On. Oh, BTW I'm not aware of the MM having a VFD drive fan motor on the internal side "only manual" .

[PonyUP]

I never allow the car (as much as I love her) to take control.......

No Automatic Temp control - All manual controls of temp and fan speed.

Mark

Are you losing fan speed while driving, or is it only happening when stopped at a light or in traffic. I know mine slows down when stopped, but not too much

[Bigdogjim]

If turn up the music you will not notice the fan speeds changing:)

[WhatsUpDOHC]

Ahhh..Ohhhh...for some reason I was thinking fan speed being the radiator fan :rolleyes:."made me lol though". But now thinking about it, check out the battery or the alternator output volts when the compressor kicks on could be a low voltage condition causing everything to dim or slow down for a moment. Now moving On. Oh, BTW I'm not aware of the MM having a VFD drive fan motor on the internal side "only manual" .

I was thinking that the variability of the fan speed could be the battery and, guess what, my battery just died!

I'm sitting in Barnes and Noble waiting for it to be replaced at Sears (Platinum battery to match the platinum/SB car).

Will post if this fixed the fan speed issue.

Thanks!

Mark

[Blackened300a]

I was thinking that the variability of the fan speed could be the battery and, guess what, my battery just died!

I'm sitting in Barnes and Noble waiting for it to be replaced at Sears (Platinum battery to match the platinum/SB car).

Will post if this fixed the fan speed issue.

Thanks!

Mark

The battery would have nothing to do with the fan while your driving. You should probably have your alternator checked out while your there as well.

[Bigdogjim]

I agree with Paul! Weak battery will not affect the blower fan while driving. Have your charging system checked.

[hwy73]

I think his Blower Control Module is on the way out. My car did the exact same thing coming home from Carlisle. On Sunday morning leaving the hotel, the A/C blower stopped running. When we got to the fairgrounds I made the "temporary adjustment" with the butt end of a screwdriver to get it going again. Second time since I had the car (bought new) that it did this. Then while driving home on the turnpike, the blower would vary its speed from full blast to nothing and back again. Another "adjustment" at a service area fixed it for the ride home. So I have to pull it and either make the repair or just replace it, but I haven't touched the car since we got home from Carlisle, its been either 100* or rained and the good thing about retirement is I don't have to work in those conditions like I did for 27 years if I don't want to.

[WhatsUpDOHC]

I think his Blower Control Module is on the way out. My car did the exact same thing coming home from Carlisle. On Sunday morning leaving the hotel, the A/C blower stopped running. When we got to the fairgrounds I made the "temporary adjustment" with the butt end of a screwdriver to get it going again. Second time since I had the car (bought new) that it did this. Then while driving home on the turnpike, the blower would vary its speed from full blast to nothing and back again. Another "adjustment" at a service area fixed it for the ride home. So I have to pull it and either make the repair or just replace it, but I haven't touched the car since we got home from Carlisle, its been either 100* or rained and the good thing about retirement is I don't have to work in those conditions like I did for 27 years if I don't want to.

Still happening - The alternator/charging system is OK according to Sears.

What does a Blower Control Module cost to repair - Anyone - Will I beat my deductable ($100)? Should I have the "Blend Door" replaced while they're in there?

Mark

[hwy73]

BCM is about $45 to 50 for the part, dealer would get you for at least an hour for the repair I would think. You get at it from under the hood. Blend door is an entirely different operation from behind the dash.

http://www.mercurymarauder.net/forums/showthread.php?t=48707&highlight=blower+control+modul e

[RF Overlord]

The blend door affects ONLY the temperature of the air...it has nothing to do with fan speed or which outlets the air blows from.

[WhatsUpDOHC]

The blend door affects ONLY the temperature of the air...it has nothing to do with fan speed or which outlets the air blows from.

I know allllllllll about the Blend Door. I thought that I had a Blend Door problem as I couldn't dial up the heat with the A/C blowing MAX (My daughter was freezing - I finally choked down the dash vents).

It was a failed Blend Door on my 98 CV that got me started looking for a replacement (I had been behind the dash and didn't want to do it again - Or pay $800).

Looking in the paper for replacement CV's led me to the MM.

I'll try replacing the Blower Control Module.

Thanks!

Mark

[4play]

it's the blower motor control module, when they fail they usually fail in the high speed setting your car is trying to hold it at lets say 60% blow speed but the module is shorting out inside causing the fluctuation. mine did the exact same thing last year. I bet if you manually set it to max speed it will hold steady. replace the BMC and it will be fixed.

[Chevyguy]

You can re solder the transistor on the BMCC. Did it on my Lincoln still works perfectly