2001 S40 1.9T ac and heater problems

sdavis · Post by **sdavis** » 04 Dec 2009, 13:26

I have an '01 S40 1.9T with 160k miles. The entire vehicle is in a little bit of disrepair but I just picked it up cheap. I want to fix it myself. It has a few problems but I want to just tackle them one at a time. My first attention will be the heater/ac. The blower blows constantly with no responce to the fan speed dial. Secondly it only blows through the dash so there is no responce to the zone dial. Third, both heater and ac seem to only work in the moderate temp-not real cold ac and not real hot heat so apparently the temperature dial has no response either. Any suggestions on where to start. I saw a previous exchange where someone had attached a pdf titled S40 climate unit but the file could not be opened after I downloaded it. It said the file was corrupt. I thought maybe that could at least give me some insight to what I am going to be dealing with. I have not taken anything apart yet so I don't know what I will find.

Post by **billofdurham** » 05 Dec 2009, 12:10

Welcome to Matthew's Volvo Site.

The blower blows constantly with no responce to the fan speed dial.

This is a common problem on the S/V40 and is usually the resistor pack for the blower motor. It is easy to change:

S.V40 heater resistor pack.pdf: (535.44 KiB) Downloaded 2028 times

The packs are not very expensive but, if you are handy, you can make an even cheaper repair by following this.

Regarding the .pdf file, I have checked it and it downloads for me. Is your Adobe reader OK?

Bill.

sdavis · Post by **sdavis** » 07 Dec 2009, 06:09

I can not tell you how useful this information is. Thank you very very much. I have ordered the transistor and will send another message once I have completed the repair. I am going to send a donation as well. Thanks again.

sdavis · Post by **sdavis** » 08 Dec 2009, 13:20

The repair went well. Your description was most helpful. Thank you, thank you, thank you. All climate control dials are now working properly but I have no heat from heater. The engine temp is on the low side of center on the dash and it has plenty of coolant. I don't know what temperature thermostat this thing uses but maybe I should try a hotter one? Or does this sound like something different?

Post by **billofdurham** » 08 Dec 2009, 15:18

You are welcome.

The needle should be about halfway up the temperature gauge. I would suspect the engine thermostat needs replacing.

Bill.

sdavis · Post by **sdavis** » 08 Dec 2009, 15:50

That actually was my first thought as well. Thanks again.

sdavis · Post by **sdavis** » 15 Dec 2009, 12:01

I have replaced the thermostat and still no heat. Do you have any heating system diagrams or thoughts where to go with my efforts next?

Post by **billofdurham** » 15 Dec 2009, 12:24

If your system is Electronic Climate Control (ECC) it will store fault codes related to the heater and indicate this by flashing the AC 'Off' light for about 20 seconds when the ignition is first switched on. Does this happen?

One other thought I did have was a possible air lock in the heater unit. Check the two pipes at the bulkhead (firewall) to see if they are both hot.

Bill.

sdavis · Post by **sdavis** » 15 Dec 2009, 13:08

Apparently I have no ECC (no flashing light on AC off) but it does look like a circulation issue in the heater unit. The hose that is closest to the drivers door (left side facing forward) is not hot but the other is.

Post by **billofdurham** » 15 Dec 2009, 15:47

The pipe that is hot is the inlet pipe which indicates the heat exchanger is not getting a supply of hot water. This could be a blockage - rare, a shut off valve that I can't find on the parts list or an air lock.

The last one is the easiest to try to sort out.

I would suggest a complete drain and refill of cooling system, catching the coolant in a container to re-use it. Leave the heater control on max and refill very slowly, massaging the radiator hoses to help move any air.

Keep us informed.

Bill.