blower motor keeps running whether car is on or off

bobb4503 · Post by **bobb4503** » 26 May 2011, 09:55

i have a 2001 v70 t5.
the blower motor runs at full speed regardless of whether the car is running or not running with or without the key.
it will run until it kills the battery.
i have resorted to removing the fuse to stop it from draining the battery every night.
the system says there are two error codes, but neither my mechanic with the snapon scanner with all the bells and whistles nor the local volvo dealer can pull any codes from the car.
the car additionally has on several occasions just shut down completely while driving along.
all the lights and accessories just go off and the car drifts to a stop.
it will not turn over or even click like a low battery condition would.
we can restart it with a garage style 120v battery charger, but not with a portable start pak or another automobile jump either directly to the battery or using the posts under the hood.
the only forensic evidence we can find is that the battery is fully drained.
the battery, alternator, starter and starting system have tested good without fluctuation on several occasions.
we have replaced the battery just in case.
while the car is idling, there is a slight fluctuation in the system voltage at about 14 volts with no accessories running. it varies plus or minus 0.25 volts.
* HELP *

Post by **JRL** » 27 May 2011, 05:44

It's supposed to run on an 01 for up to 45 minutes after you shut the car off.
It's called the afterblow system and it clears out the AC system
Check your running time
If it shuts off after about 45 minutes it's working properly
You may need a new battery
If that didn't work there is a fault glitch in the timing.
Probably needs to be reset for starters or just have the function removed if you don't want it, (by Volvo thru VIDA), it CAN be turned off

bobb4503 · Post by **bobb4503** » 28 May 2011, 11:46

thank you for the response JRL,
it will keep running until the battery dies.
i did put a new battery in it just in case that was the problem early on.
additionally, when i insert the fuse evening or morning it will start running with or without the key.
what do i tell them to get them to turn that feature off at volvo ?

could the regulator in the alternator be the cause of the sudden shut down problem ?
if the alternator is working sporadically because of the regulator could that cause the car to drain the battery and just quit when the battery runs out ?
it happens so seldomly that no one can diagnose it.

Post by **DGM** » 30 May 2011, 18:34

I would check the power stage unit feeding the blower motor for short circuit. It is located in the ventilation tunnel near the blower, passenger side.

The later part of this video is talking about the condition.

Older units were using resistors to adjust motor speed. They are known as "blower motor resistor". Newer models use power transistors to drive the blower motor. See the following link for your application.

http://www.fcpgroton.com/category-exec/ ... by_year/51

Your motor must be in good condition before to install it. If its drawing too much current, the new unit can be destroy. Many change them as a pair to be safe.

See the wiring diagram for the V70 2002;

https://www.matthewsvolvosite.com/volvo-wiring-diagrams/

Page 95, unit 4/31.

Page 101 in the PDF format.

Good work!

glibaert · Post by **glibaert** » 23 Sep 2012, 05:29

Hi, I was wondering if you managed to isolate the fault on your Volvo, I have recently experienced exactly the same issue with my 2008 V70. For now I have pulled the blower fuse to prevent battery drain but was wondering if you found a sticky relay or switch on your system that made a quick-fix. Thanks, Graham.

VolvoOregon · Post by **VolvoOregon** » 06 Nov 2017, 10:43

Hi Graham,

Did you figure out your fan blower issue? I have a 2006 S80 with 32,000 miles on it doing the same thing. Any leads you could pass on? -- James in Oregon

VolvoOregon · Post by **VolvoOregon** » 06 Nov 2017, 10:59

Hi,

How was your problem fixed? I have same issue with a 2006 S80.

James

rechedfox · Post by **rechedfox** » 19 Nov 2017, 06:56

I had a problem similar to your continuous blower motor operation with my '04 XC70. The interior AC blower would continue to run after the car was turned off and eventually kill the battery. Replacing the "Power Transistor" under the dash on the passenger side of the car eliminated the problem. While troubleshooting I did not see any advice to also replace the blower, however, so I didn't. I haven't, as yet, had any repetition of the problem.

Post by **jimmy57** » 19 Nov 2017, 09:02

On the P2 models this is a common failure. I see the same failure on many other makes using transistor blower speed regulation. The most common cause is blower motor having an issue like dry bushings though cabin filter being plugged also causes much higher blower current.
On a 2008 XC70 the transistor speed regulation circuit is integral with the blower motor as it is a brushless motor and the transistor circuit is also the dc to ac inverter to make a brushless 3 phase motor operate. I wonder if the 2008 MY XC70 in UK is a P2 or did they have split year with some 2008 as P2 and others are the P3 version?

Post by **mrbrian200** » 19 Nov 2017, 12:37

I'm not expressly familiar with the inner workings of the electrical portion of the ignition switch, however, when I first bought my S60 after it had been basically sitting for the better part of six months I noticed something in the ignition switch was a little 'sticky'. A few times the blower would continue after I shut the car off until I pulled the key all the way out. This behavior stopped after a couple weeks of daily use. I was also noticing issues with a battery drain when the car was off/overnight that seemed to resolve on its own as the mechanism freed up and no longer was causing this after blow 'symptom'. To this day, once in awhile, the fan will continue a little longer, maybe 1/2 to a full second after the ignition is turned all the way off. I have noted many chassis parts on these seem to be lubed internally with a white lithium or silicone based lubricant that gets tacky and stiff with age, which includes door and trunk locking mechanisms etc. If that's what the used inside the ignition electrical switch assembly I'm sure the matter or correcting it would be to clean out the original lubricants with a solvent and refresh it with a high quality non conductive synthetic/dielectric grease. My trunk locking mechanism was becoming problematic on cold days, this is what fixed it. I wouldn't be surprised if the ignition switch has the same stuff in it.