Heater/defroster fan not working, Help!

cedarsanctum

re: Member
I need some assistance. I am in the mountains working for 2 weeks and came up here without any of the owners manuals or anything that would tell me which fuses to look at. The heater blower fan was not working on the way up here, but since the first leg of the journey was at highway speed, i didn't notice. As soon as we got to the slower travel mountain road the windows started to fog up, and nothing i could do would make it work. The lights on the dash for the fan work, but nothing comes out. Shutting it all down and restarting did not work. It's been raining constantly since i got here, so i haven't bothered to investigate much yet, and snow is expected for tonight. With a little luck i might get a little dry spell before i leave on the 7th to look at this.
Has anybody got any suggestion what to check? Does anyone know which fuses to check?
Fortunately, we have internet up here, so having the Forum available is a great resource.
Thanks.
Jef
 

lockrob

Member
Had to replace the blower motor on mine at about 45000 miles.Not hard to change need to remove glovebox to get it out.The motor comes out with a twist and pull.There is a tab you have to depress then turn.It looks like they made it easy to change because they knew you would have to.
If I remember the motor was close to 200 $
 

wildimaginations

Wild Imaginations
The fuse is located under the dash on the left side of the driver's side footwell. There are 2 sets of fuses. Look for #12 on the bottom set. It's a 30a fuse. Good luck.
 

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autostaretx

Erratic Member
Does the fan work at HIGH speed? If so, it could be the resistor block (if the NCV3 still uses one).
--dick
 

jdcaples

Not Suitable w/220v Gen
From the 2007 Service Manual CD (All I have access to right now)....

Let me know what you need and I'll try to get the info for you....

-Jon

FRONT BLOWER MOTOR


WARNING: Disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to take the proper precautions may result in accidental airbag deployment and possible serious or fatal injury.

NOTE: For circuit descriptions and diagrams, refer to Air Conditioning/Heater in Group 8W - Wiring Diagrams.



OPERATION
Possible causes of an inoperative blower motor include:

Open fuse
Inoperative blower motor resistor or power module (depending on application)
Inoperative blower motor switch
Inoperative mode control switch
Inoperative blower motor
Inoperative blower motor circuit wiring or wire harness connectors


NOISE
To determine if the blower motor is the source of the noise, simply switch the blower motor from Off to On. To verify that the blower motor is the source of the noise, unplug the blower motor wire harness connector and operate the heater-A/C system. If the noise goes away, possible causes include:

Foreign material on fresh air inlet screen
Foreign material in blower wheel
Foreign material in the HVAC housing
Improper blower motor mounting
Deformed or damaged blower wheel
Worn blower motor bearings or brushes


VIBRATION
Possible causes of blower motor vibration include:

Improper blower motor mounting
Foreign material in blower wheel
Deformed or damaged blower wheel
Worn blower motor bearings
 

cedarsanctum

re: Member
Thanks Jon,
Wildimaginations sent about all i can check on here. When the weather warms a bit and we thaw, i'll investigate. We had 10 degrees the other morning, and still have frozen snow on the ground. Fortunately i don't have to leave until next Friday.

The other problem that has cropped up is condensation building up inside and dripping onto the overhead console, putting out the interior lights and probably the sunroof. Again. Last time it was the antennae leaking, maybe. Gonna have to rethink the insulation in the ceiling to limit the condensation up there.

Jef
 

jdcaples

Not Suitable w/220v Gen
Not that this helps now, but Bruce (bblessing) recommended rain gutter sealant for the gasket. The antenna base is - surprise - sold as an assembly including the gasket that seals the hole in the metal. The tech told me there are three threads on the fasteners that hold it on; stupid design. Anyway, if it's the antenna gasket - at $300 + an hour or two of labor to replace it - I think Bruce, as usual, is correct.

I wish I could be more help, Jef. Have a safe, uneventful trip back. May the weather be with you.

-Jon
 

wildimaginations

Wild Imaginations
I have a similar problem right now. My blower will not turn though I have checked the connector and it shows 12 volts but when it's plugged in, the voltage drops to zero. My ground connection is good. I've already replaced the resistor block and still no blower action. I'm now looking for the control box to the blower motor. Can anyone tell me where the control box is located? I'm sure it's not on the center control because all the wires attached to it are too tiny to power up the blower. There's got to be a relay box somewhere but I don't have a schematic location where it's at. Any help is appreciated.
 

wildimaginations

Wild Imaginations
Ok, finally got this thing working. Found that the pin connectors behind the ac/heater controls were suspicious. I removed both connectors behind the control and checked for any signs of corrosion. Then I replaced the connectors back on the controller. AND WALLA!!! The blower is working once again. Those tiny pins are really small and it's possible that the one pins leading to the blower resistor was not sending a signal from the controller. Anyway, I hope this helps for cedarsanctum and anyone else who is having problems with their blower fan.:clapping:
 

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cedarsanctum

re: Member
Excellent write-up WI. This would help a lot if i had any of my tools up here. If i can find some drivers and bits, i'll sure check those connectors. The fuse is good, thanks for the location. As it is, this should be covered by warranty, when i get back in town. I'm just hoping the weather holds clear for the drive home.
It's been down to 10 at night, holding around 16-20 for 3 nights now. Snow is staying hard packed, but easy to drive on. Weather is clear and dry. Beautiful.
Here's a pic from early in the storm, parked where i live while here. There is an additional 6 inches on top of this.
 

Attachments

cedarsanctum

re: Member
Not that this helps now, but Bruce (bblessing) recommended rain gutter sealant for the gasket. The antenna base is - surprise - sold as an assembly including the gasket that seals the hole in the metal. The tech told me there are three threads on the fasteners that hold it on; stupid design. Anyway, if it's the antenna gasket - at $300 + an hour or two of labor to replace it - I think Bruce, as usual, is correct.

I wish I could be more help, Jef. Have a safe, uneventful trip back. May the weather be with you.

-Jon
Thanks again. This time it's not the antennae, it's from condensation collecting on the inside of the roof and dripping down from a misplaced piece of reflectix. Lesson learned from this is to NOT cook inside when we have to keep it so closed up because of the cold. Good thing we don't have to cook in here all the time, or at all while here.
I must address the issue of excessive condensation collecting inside the ceiling, and intend to create a tighter vapor barrier with materials already up there, but not sealed up when installed. Now i get to go back and do a lot of it again.
There is a huge learning curve with this process of building an RV, and a lot of it is only available with experience. I will make it work, but i'm not there yet.

Jef
 

220629

Well-known member
...
If so, it could be the resistor block (if the NCV3 still uses one).
--dick
Dick,
We learned from Jon's info that they may have one.

OPERATION
Possible causes of an inoperative blower motor include:

Open fuse
Inoperative blower motor resistor or power module (depending on application)
Inoperative blower motor switch
Inoperative mode control switch
Inoperative blower motor
Inoperative blower motor circuit wiring or wire harness connectors
Unless the "or power module (depending on application)" comment means that if you have the Power Module, you don't have a resistor? vic
 

Graphite Dave

Dave Orton
My thought on the roof insulation is to eliminate as much as possible any air spaces. Without air that contains moisture, the condensation should be minimized. I am going to apply adhesive backed sound deadening material to the roof steel and then fill the space with rigid foam board and spray foam. What do you think of this approach?
Please describe what you now have. Are there air pockets in your van?
 

autostaretx

Erratic Member
vic said:
Unless the "or power module (depending on application)" comment means that if you have the Power Module, you don't have a resistor?
In another recent thread, Jon posted links to the two variations (ATC,MTC) of the schematics... one with a resistor block, one with a power module.
So it would appear it's an either/or situation.
--dick
 

cedarsanctum

re: Member
My thought on the roof insulation is to eliminate as much as possible any air spaces. Without air that contains moisture, the condensation should be minimized. I am going to apply adhesive backed sound deadening material to the roof steel and then fill the space with rigid foam board and spray foam. What do you think of this approach?
Please describe what you now have. Are there air pockets in your van?
I stayed away from the rigid foam because it squeaks, and the spray foam because of off-gassing. I also had a LOT of trouble getting anything to stick to the roof. Even the metal duct tape didn't stick at all, fell right off. Also, i was thinking that applying things right to the metal could potentially trap moisture and cause bad spots to appear in the future.
What i have is a layer of reflectix, as much closed cell upholstery foam as would fit, and another layer of reflectix. None of this was attached to the ceiling, it is held in place by the factory headliner, leaving an air space above to ventilate (thinking like a home builder here) and let moisture out. What it did was let the cooking moisture in to condense on the metal skin. This is the first time it's been this bad, but it's the coldest we've seen with the new heater also.
My newest thinking is to tape all the bottom layer of reflectix together and seal it to the body, making the insulation and air spaces above separated by a vapor barrier. Won't happen until dry, warm weather and i can get everything opened up and dried out, and i have the time available to take it apart for more than 2 weeks.
Hope it's OK to hijack your own thread.
Jef
 

220629

Well-known member
...
Hope it's OK to hijack your own thread.
Jef
Jeff,
It is, but then you need to pay tribute to all Sprinter-source members. I suggest you start with me.

Many of you guys put a lot of thought and effort into making your Sprinters perfect. That is very admirable. :thumbup: Your wife's next husband will really appreciate it I'm sure. :tongue: My wife's next husband will get a rust spotted, not very clean, dog hair filled wreck. That's my reason for it being in the condition it is and I'm stickin' to it. :crazy: :cheers: vic
 

wildimaginations

Wild Imaginations
The snow looks like a lot of fun but I'm too scared to drive into snow anymore. Had a bad experience where on a slight decline, couldn't slow down. Thank goodness the light turned green at the intersection by the time I slid right on through it. Just send more pics of your snow adventures and I will be happy with that.
 

cedarsanctum

re: Member
The snow looks like a lot of fun but I'm too scared to drive into snow anymore. Had a bad experience where on a slight decline, couldn't slow down. Thank goodness the light turned green at the intersection by the time I slid right on through it. Just send more pics of your snow adventures and I will be happy with that.
Here's a picture of my daily commute. I walk across the Breitenbush river several times a day on a footbridge. This photo was also taken early in the storm that brought this snow.
10 9:07 AM.jpg

Looks like the snow might break up before i leave. Temps have been above freezing and rain is expected by Friday, the day i leave. Hoping it doesn't fog up the windows very bad. The overall condensation problem i had last week is easing a bit since i stopped trying to cook inside. When i get home, i'll try to dry it further.
 

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