heater blower is revving up and down when running
#21
It's located on the passenger side behind the glove box, inside the air duct, maybe knee high off the floor. If you drop the kick panel above your feet you can see the 2 phillips screws and the electrical connector (the black part in the picture above). The silver heat sink is inside the air duct so you cannot see it until it's removed.
For me the hardest part was getting to one of the phillips head screws. I removed the glove box and drilled an access hole in the metal bar blocking the screw. (I'm not sure if the metal bar is removable) I could then reach the screw. The whole unit wiggles out between the metal bar and the air duct. If you can get the metal bar out of the way it would be 100% easier. The glove box covers the drilled hole so it still looks nice.
Replace the cabin air filter while you are in there. It's located beside the resistor.
For me the hardest part was getting to one of the phillips head screws. I removed the glove box and drilled an access hole in the metal bar blocking the screw. (I'm not sure if the metal bar is removable) I could then reach the screw. The whole unit wiggles out between the metal bar and the air duct. If you can get the metal bar out of the way it would be 100% easier. The glove box covers the drilled hole so it still looks nice.
Replace the cabin air filter while you are in there. It's located beside the resistor.
#22
#23
Thanks. I have ordered a replacement. I also replaced the cabin filter and besides the dirt and crap in the filter itself, I found a couple handfulls of leaves and other deteriorating stuff in the space next to the filter. I reached in with my left hand, fingers toward the right side of the car and there it was.
I'm not sure how all this stuff is getting in.
The blower had also been making a low rumble at higher speeds, like 4, 5, a sound it hadn't made when new. I looked from below to the right of the cabin filter and saw that the blower motor could be removed with just three Torx screws. It came straight down with the round blower cage attached and the cage was full of leaves (!!), which caused it to be off balance at the higher speeds and generate the low rumble. Next time you have the footwell cover off, you might want to take a look. Torx 10 or 15 and take off the screw toward the front of the car first - it's easier to get to with the motor firmly in place.
Regards,
I'm not sure how all this stuff is getting in.
The blower had also been making a low rumble at higher speeds, like 4, 5, a sound it hadn't made when new. I looked from below to the right of the cabin filter and saw that the blower motor could be removed with just three Torx screws. It came straight down with the round blower cage attached and the cage was full of leaves (!!), which caused it to be off balance at the higher speeds and generate the low rumble. Next time you have the footwell cover off, you might want to take a look. Torx 10 or 15 and take off the screw toward the front of the car first - it's easier to get to with the motor firmly in place.
Regards,
#24
How do you get this unit out of the blower housing? The upper screw on mine was already removed, so someone else has been here before me. But with both screws out, I cannot see how to remove the unit. Is bending the steel rail under the glove box the only method?
Thanks,
Thanks,
Last edited by kstinmb; 09-16-2014 at 02:01 PM. Reason: Brain lag.
#26
I just bought a 2002 Volvo S40. This is my first Volvo and I'm not very familiar with them. I've had the car for 1 week. I've been using the heater a bit at night, and I noticed the blower is acting very strangely.
I have it on manual, with front air vent exhaust, and no matter what speed or temperature air I set, the blower revs up and down constantly. If I set it on 1 for example, it runs low, then revs up and the blower increases like I just turned it up to 3 or more, then it revs down again, then back up, etc. - if I turn it up higher like 3 or 4 or 5, the same thing happens - the fan speed seems to be all over the place. Even with me in park, with my foot off the accelerator, the fan speed is still up and down constantly, every few seconds. It definitely doesn't seem right, but I"m unfamiliar with Volvos. Is this normal? Should this be happening?
I would think that if I set it to a specific speed, like 1, then I would want it on 1, not up and down in speed. The circulate is turned off, but I tried it with circulate on also and there was no difference. It's been doing this since I got the car last week. Any idea why this i happening? What should I do about this?
I have it on manual, with front air vent exhaust, and no matter what speed or temperature air I set, the blower revs up and down constantly. If I set it on 1 for example, it runs low, then revs up and the blower increases like I just turned it up to 3 or more, then it revs down again, then back up, etc. - if I turn it up higher like 3 or 4 or 5, the same thing happens - the fan speed seems to be all over the place. Even with me in park, with my foot off the accelerator, the fan speed is still up and down constantly, every few seconds. It definitely doesn't seem right, but I"m unfamiliar with Volvos. Is this normal? Should this be happening?
I would think that if I set it to a specific speed, like 1, then I would want it on 1, not up and down in speed. The circulate is turned off, but I tried it with circulate on also and there was no difference. It's been doing this since I got the car last week. Any idea why this i happening? What should I do about this?
The climate control ***** use potentiometers to control the blower speed, vent selection and temperature. Over time minute dust particles work their way into them, and they even corrode a bit inside due to humidity, and they start sending erratic signals to the controller. I found several sources online that recommended using a cleaner like Deoxit 5 to fix potentiometer issues. Bought a small can at Radio Shack for $13. Then pulled the climate control module out of the dash and took it apart down to the circuit board, not too hard to do, a few screws and everything else is snapped together. Then sprayed the pots down with Deoxit while slowly turning the pots back and forth to work the cleaner around inside. Basically followed the directions on the can.
Total success, the blower now blows at consistant speeds at every selection. I did this back in February and its still working fine.
I cannot say for sure that this will work for you though. I had also read where many people had issues and resolved it by replacing the blower resistor... so maybe something to try if that fails?
Good luck and let us know how you make out.
#27
How do you get this unit out of the blower housing? The upper screw on mine was already removed, so someone else has been here before me. But with both screws out, I cannot see how to remove the unit. Is bending the steel rail under the glove box the only method?
Thanks,
Thanks,
However, a couple of days later we had a 90+ degree day, and right after starting the car and setting the A/C on Auto/Auto, the ventilator began its start/stop/start/stop failure again. If the car is restarted during the day, no problem and if the ambient temperature is below 85 or so, no problem, so we may just live with it from here out. I have no further ideas or information.
Regards,
#28
If replacing the resistor does not work before doing any further troubleshooting take each of the ***** on the climate control panel and very quickly turn each of them back and forth (clockwise/counterclockwise) about 20 times (especially the temp adjustment ****). See if that helps. Sometimes the potentiometers in the ccm get gunked up and the friction cleans them up.
If that doesn't work, re-soldering the contacts for the temp control **** within the ccm is worthwhile. Taking it out is pretty easy stuff. Then just bring it over to a corner store electrician and ask them to resolder the dial contacts.
If that doesn't work, you can get someone to replace one of the potentiometers for you (they cost about $5) or you can listen to volvo and buy an brand new ccm for $600 or a used one from scrapper for about $100...the problem with the used ones is that this fault is quite common so you may find yourself back at square 1.
I resoldered AND replaced the POTS...in retrospect, I think I was fine with simply resoldering.
If that doesn't work, re-soldering the contacts for the temp control **** within the ccm is worthwhile. Taking it out is pretty easy stuff. Then just bring it over to a corner store electrician and ask them to resolder the dial contacts.
If that doesn't work, you can get someone to replace one of the potentiometers for you (they cost about $5) or you can listen to volvo and buy an brand new ccm for $600 or a used one from scrapper for about $100...the problem with the used ones is that this fault is quite common so you may find yourself back at square 1.
I resoldered AND replaced the POTS...in retrospect, I think I was fine with simply resoldering.
Last edited by pierremcalpine; 10-22-2014 at 08:35 AM.
#29
I had a problem with the blower for the 2nd time. Several years ago, I removed the climate control module & replaced the capacitors as someone noted earlier. I also replaced the power transistor under the glovebox. I can't say that either fix corrected the problem but it was livable until recently.
This time, I found a replacement transistor for $12 on ebay and tried soldering one in. My soldering skills aren't the best. The leads were really short & there was no service loop to work with. After struggling for about 2 hours, my attempt to fix this failed. I gave up & bought a new assembly from the dealer for about $90. Before I was able to get it installed, I just plugged it in for the ride home. By the time I got home, the transistor unit got very hot. I guess they mount it inside the duct upstream from the heater core to keep it cool. I was surprised how hot it got on a cold day.
I was able to reinstall it by flexing the sheetmetal bar out of the way. Now it works pretty well again. However, the fan speed still rises & falls erratically but I'm guessing this is because of the auto-climate control.
As with most repairs, this is pretty easy the 2nd time.
This time, I found a replacement transistor for $12 on ebay and tried soldering one in. My soldering skills aren't the best. The leads were really short & there was no service loop to work with. After struggling for about 2 hours, my attempt to fix this failed. I gave up & bought a new assembly from the dealer for about $90. Before I was able to get it installed, I just plugged it in for the ride home. By the time I got home, the transistor unit got very hot. I guess they mount it inside the duct upstream from the heater core to keep it cool. I was surprised how hot it got on a cold day.
I was able to reinstall it by flexing the sheetmetal bar out of the way. Now it works pretty well again. However, the fan speed still rises & falls erratically but I'm guessing this is because of the auto-climate control.
As with most repairs, this is pretty easy the 2nd time.
#30
Replaced control panel - no go - now what?
Back again. To recap, we have a 2001 S40 and for many years (!!) now, the blower runs erratically, fast/slow/stop, no matter the settings, heat or A/C, speed number or AUTO.
I replaced the entire Final Stage Resistor and it had no effect ($65).
A couple of weeks ago I bought a replacement control panel from eBay ($100). I know it's the right one from the part number, 30612628.
But this also has had no effect. The blower still runs fast-slow-fast-stop-slow-fast, etc. The one nise aspect is that we now have buttons which aren't sticky!
Is there something else that controls the speed of the fan?
Has anyone replaced the blower motor itself?
Thanks,
-stephen
P.S. In an earlier post I mentioned that the blower, when running, had a very loud humming, brumming, vibration sound. With three torx screws I was able to drop the blower motor and cage straight down and here's what I found:
These oak leaves had fallen down through the air inlet and their weight unbalanced the blower cage, causing the vibration.
I replaced the entire Final Stage Resistor and it had no effect ($65).
A couple of weeks ago I bought a replacement control panel from eBay ($100). I know it's the right one from the part number, 30612628.
But this also has had no effect. The blower still runs fast-slow-fast-stop-slow-fast, etc. The one nise aspect is that we now have buttons which aren't sticky!
Is there something else that controls the speed of the fan?
Has anyone replaced the blower motor itself?
Thanks,
-stephen
P.S. In an earlier post I mentioned that the blower, when running, had a very loud humming, brumming, vibration sound. With three torx screws I was able to drop the blower motor and cage straight down and here's what I found:
These oak leaves had fallen down through the air inlet and their weight unbalanced the blower cage, causing the vibration.
#31
Hi kstinmb,
If the module that you bought was used there is every chance the pots in it are bad too.
You can sort of test if its the pots by tapping on the fan speed **** from the side. I can tap mine and get a change in behaviour, either it settles down and blows normal or it starts blowing full speed again. Tapping and getting a direct response could only be from a bad pot.
I've about given up on mine and am just going to live with it. I cleaned them with Deoxit and that fixed it for about a year, but now its acting up again. I'm tired of dealing with it and brand new modules are rediculously high $$$$$$$.
As for your question, I do not think anything else besides the pots or resistor would cause this. I can't think of any way a bad motor would cause these symtoms.
If the module that you bought was used there is every chance the pots in it are bad too.
You can sort of test if its the pots by tapping on the fan speed **** from the side. I can tap mine and get a change in behaviour, either it settles down and blows normal or it starts blowing full speed again. Tapping and getting a direct response could only be from a bad pot.
I've about given up on mine and am just going to live with it. I cleaned them with Deoxit and that fixed it for about a year, but now its acting up again. I'm tired of dealing with it and brand new modules are rediculously high $$$$$$$.
As for your question, I do not think anything else besides the pots or resistor would cause this. I can't think of any way a bad motor would cause these symtoms.
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