v40 heater

bilfish · Nov 5th, 2011, 21:03

Hi anybody out there know how to fix 04 volvo V40 diesel estate heater blower doesn;t work and only comes on intermittantly when I start the car with heater controls already set. comes on maybe once a week, while working if i reduce blower speed blower goes off.

drh3 · Nov 8th, 2011, 23:46

My 02 V40 is having the same problem. Over a year or so, the fan control has become less reliable. In hot weather it is fine, but speed control was all over the place. As the weather gets colder, the fan takes longer and longer before kicking in. The symptom starts with a dead control panel - the backlights are on, but none of the control buttons will light. After a random amount of time, the orange light on the AC button flashes and eventually goes solid and the fan will start. I've replaced the infamous fan resistor as well as the pollen filter as a cheap starter for 10. Still the same problem. I had read elsewhere that the problem can be dry solder joints on the printed circuit board in the control unit on the dashboard, specifically the 3 legs of the fan speed potentiometer. I removed this and sweated and then resoldered the legs. This certainly had an effect, but didn't fix the problem. I then bought a second hand unit from Ebay - same problem. I bought a further 2 units from scrap yards - still the same problem. I spoke to a Volvo mechanic who said this was a common fault in the V40 and that replacement units were a "fingers crossed fix". He suggested that they would all be of a similar age and therefore at the same point of failure. I've been quoted £520 inc VAT for a new one from Volvo, so am trying to avoid that for the time being. I have one more coming from a breaker's yard on Thursday - if I have the same problem again, it looks like Volvo shareholders will be benefitting from my hard-earned.

If you need any info on how to replace the bits yourself (resistor, pollen filter, control unit) let me know - I've become an expert in the past couple of weeks! If I get a fix, I'll let you know...

gatos · Nov 9th, 2011, 00:46

I have just fixed one today. One of the joints was dry so I re-soldered the controller

drh3 · Nov 12th, 2011, 01:37

I need to brush up on my soldering! Do you offer a soldering service :o)

gatos · Nov 12th, 2011, 02:02

Quote:

Originally Posted by drh3

I need to brush up on my soldering! Do you offer a soldering service

)

lol. All I did was to use the tip of the soldering iron to melt the existing bit and added a tiny bit of lead-tin alloy on top. 2 minute job.

If you want to send it, I can do it for free. But I am sure that a friend of yours must have a soldering iron and you could save the postage

drh3 · Nov 12th, 2011, 02:12

I've had another go tonight, but got a better desoldering pump and sucked the joints totally dry and removed the potentiometer, cleaned it up and then resoldered the joints. I suspect when I sweated the joints before and added new solder then the old solder was in such a bad state that it just kept oxidising on the joint, leaving a dry joint. Fingers crossed - will test it tomorrow. New joints look a bit shinier than the old ones did. Just hope I haven't overheated the pads on the board, but I've got a few boards in my collection now!

What was the problem with yours? Was it intermittent or totally dead?

gatos · Nov 12th, 2011, 02:48

It wasn't mine. It was Siamblue's. The fan was erratic going up and down randomly. I had a spare one, which I gave him and I kept his one. Now I fixed it, I have another spare one for next time...

drh3 · Nov 12th, 2011, 11:38

Yes - it seems to be a common fault. I've had the V40 for 2 years now (02 plate) and the fan became erratic a month or so after buying it. I didn't think a lot of it, but it just got worse and worse to the point that it packed in completely and the control panel appeared dead. At some point today, the resoldered board is going back in - fingers crossed.

drh3 · Nov 12th, 2011, 20:11

Looks like a no go with the soldering. I'm beginning to get concerned that 3 control units later, still no go. Does anyone know what other components are involved in the blower motor control. The fan works, the resistor pack on the fan has been replaced. Is there anything else upstream of the control unit that might affect its operation?

gatos · Nov 12th, 2011, 22:26

Just a silly thought. But is there any chance that you originally had climate control in your car and the other control units you tried were for simple Air Con? I know it is a far shot but you never know. You can tell you had climate if there is a tiny vent between the right 2 knobs.

If not, I am not so sure. Either you are extremely unlucky with your units or there is a problem somewhere else. But having taken apart an S40 and a V40, I have never noticed any other modules controlling the air con

Nov 5th, 2011, 21:03	#1
bilfish New Member Last Online: Feb 2nd, 2013 22:31 Join Date: Nov 2011 Location: johnstone	v40 heater Hi anybody out there know how to fix 04 volvo V40 diesel estate heater blower doesn;t work and only comes on intermittantly when I start the car with heater controls already set. comes on maybe once a week, while working if i reduce blower speed blower goes off.

Nov 9th, 2011, 00:46	#3
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	I have just fixed one today. One of the joints was dry so I re-soldered the controller __________________ Current car: 2002 S40 1.9D, 1992 240SE Nullius in Verba

Nov 12th, 2011, 01:37	#4
drh3 Junior Member Last Online: Dec 21st, 2011 23:25 Join Date: Apr 2010 Location: Knaresborough	I need to brush up on my soldering! Do you offer a soldering service :o) Last edited by drh3; Nov 12th, 2011 at 01:46.

Nov 12th, 2011, 02:48	#7
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	It wasn't mine. It was Siamblue's. The fan was erratic going up and down randomly. I had a spare one, which I gave him and I kept his one. Now I fixed it, I have another spare one for next time... __________________ Current car: 2002 S40 1.9D, 1992 240SE Nullius in Verba

Nov 12th, 2011, 22:26	#10
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	Just a silly thought. But is there any chance that you originally had climate control in your car and the other control units you tried were for simple Air Con? I know it is a far shot but you never know. You can tell you had climate if there is a tiny vent between the right 2 knobs. If not, I am not so sure. Either you are extremely unlucky with your units or there is a problem somewhere else. But having taken apart an S40 and a V40, I have never noticed any other modules controlling the air con __________________ Current car: 2002 S40 1.9D, 1992 240SE Nullius in Verba

Nov 8th, 2011, 23:46	#2
drh3 Junior Member Last Online: Dec 21st, 2011 23:25 Join Date: Apr 2010 Location: Knaresborough	My 02 V40 is having the same problem. Over a year or so, the fan control has become less reliable. In hot weather it is fine, but speed control was all over the place. As the weather gets colder, the fan takes longer and longer before kicking in. The symptom starts with a dead control panel - the backlights are on, but none of the control buttons will light. After a random amount of time, the orange light on the AC button flashes and eventually goes solid and the fan will start. I've replaced the infamous fan resistor as well as the pollen filter as a cheap starter for 10. Still the same problem. I had read elsewhere that the problem can be dry solder joints on the printed circuit board in the control unit on the dashboard, specifically the 3 legs of the fan speed potentiometer. I removed this and sweated and then resoldered the legs. This certainly had an effect, but didn't fix the problem. I then bought a second hand unit from Ebay - same problem. I bought a further 2 units from scrap yards - still the same problem. I spoke to a Volvo mechanic who said this was a common fault in the V40 and that replacement units were a "fingers crossed fix". He suggested that they would all be of a similar age and therefore at the same point of failure. I've been quoted £520 inc VAT for a new one from Volvo, so am trying to avoid that for the time being. I have one more coming from a breaker's yard on Thursday - if I have the same problem again, it looks like Volvo shareholders will be benefitting from my hard-earned. If you need any info on how to replace the bits yourself (resistor, pollen filter, control unit) let me know - I've become an expert in the past couple of weeks! If I get a fix, I'll let you know...

Nov 12th, 2011, 02:12	#6
drh3 Junior Member Last Online: Dec 21st, 2011 23:25 Join Date: Apr 2010 Location: Knaresborough	I've had another go tonight, but got a better desoldering pump and sucked the joints totally dry and removed the potentiometer, cleaned it up and then resoldered the joints. I suspect when I sweated the joints before and added new solder then the old solder was in such a bad state that it just kept oxidising on the joint, leaving a dry joint. Fingers crossed - will test it tomorrow. New joints look a bit shinier than the old ones did. Just hope I haven't overheated the pads on the board, but I've got a few boards in my collection now! What was the problem with yours? Was it intermittent or totally dead?

Nov 12th, 2011, 11:38	#8
drh3 Junior Member Last Online: Dec 21st, 2011 23:25 Join Date: Apr 2010 Location: Knaresborough	Yes - it seems to be a common fault. I've had the V40 for 2 years now (02 plate) and the fan became erratic a month or so after buying it. I didn't think a lot of it, but it just got worse and worse to the point that it packed in completely and the control panel appeared dead. At some point today, the resoldered board is going back in - fingers crossed.

Nov 12th, 2011, 20:11	#9
drh3 Junior Member Last Online: Dec 21st, 2011 23:25 Join Date: Apr 2010 Location: Knaresborough	Looks like a no go with the soldering. I'm beginning to get concerned that 3 control units later, still no go. Does anyone know what other components are involved in the blower motor control. The fan works, the resistor pack on the fan has been replaced. Is there anything else upstream of the control unit that might affect its operation?

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