Driver's side doesn't heat but passenger does

Caraduras · Post by **Caraduras** » 24 Oct 2011, 20:01

I have a 2000 S70. The AC works fine. Blower motor strong. Heater works on passenger side, but not driver's. When you adjust the driver's side temperature up you can here the damper motor click , but you still get cool or cold air. The same treatment on the passenger side changes from cold to hot air. This is a problem for defrosting in cold weather. I'm not sure if there is a damper control that isn't working or the heater core is split and perhaps clogged on one side. How can I diagnos and fix this?

kcjones · Post by **kcjones** » 24 Oct 2011, 20:48

I had this happen once.

Turns out, there are two "climate sensors" on either side near the "oh shucks" handles. Give them both a good blast of compressed air.

Mine were dirty and the climate lights started blinking and air wouldn't get hot. I guess they're sensitive to dust

Caraduras · Post by **Caraduras** » 24 Oct 2011, 21:50

Thanks. How do i get to the climate control sensor on the driver's side? What are the 'oh shucks' handles? I will give it a try.

kmg108 · Post by **kmg108** » 24 Oct 2011, 21:52

I'm really glad you asked this question. The search feature is my friend and I'm having the EXACT same problem. I thought the "oh shucks" handles were attached to the ceiling? I'm watching this thread. Thanks in advance guys.

kcjones · Post by **kcjones** » 24 Oct 2011, 22:03

Indeed they are. Next to the handles you'll see a small square plastic piece with a hole in the center.

I'm running purely on assumption that Volvo kept this part in the years to come.

kmg108 · Post by **kmg108** » 24 Oct 2011, 22:39

I just walked out there with a flashlight and saw no such animal next to the grab handles. There is simply a grab handle and nothing else. I saw some other threads about the 850 having a sensor in that location, but the original poster and myself both have the s70 (which is basically the same car as 850), but I dont see this sensor. Does anyone have a photo of it still mounted in the car? Does the s70 possibly have the same sensor that is mounted somewhere other than right next to the grab handles?

Sorry to the original poster...I hope this doesn't see like a thread jack as that is not my intention. We have the same car with the same problem and I'm seeking clarity for both of us. I will gladly start my own post on the same subject if you prefer.

kmg108 · Post by **kmg108** » 24 Oct 2011, 22:49

According to this link, the s70 and 850 are different but I can't confirm until I fix this. Assuming the info in the link is correct, it does not explain why only one side is blowing heat when the other only blows cold on any setting.

Link: https://www.matthewsvolvosite.com/forums ... 71&start=0

kcjones · Post by **kcjones** » 24 Oct 2011, 23:26

Ah, foiled again

The link you posted mentions location (for clarity):

"Only one in your car...in the dash, to the left of the climate control...find a small rectangular vent...it's in there. You can get to it if you remove the radio".

I can't find anything else on S70 differences in temps. Maybe for extra clarity, when someone with a better idea hops in, mention if you have manual or automatic climate control.

Sorry for misleading. Best of luck!

Post by **Ozark Lee** » 24 Oct 2011, 23:56

This is a classic symptom of a bad damper motor or a split shaft on the end of the damper flap door. You can get to the driver's side by removing the lower dash panel and then the "stiffener" behind the carpet. On the driver's side you should only have one motor and that is the temperature mix damper. Remove it and inspect the end of the shaft and also inspect (such that you can) the teeth on the motor gear.

If the end of the shaft is split try to save all of the pieces since it will make the repair easier.

...Lee

Caraduras · Post by **Caraduras** » 25 Oct 2011, 15:17

Thanks Y'all. These are some excellent suggestions. Just to clarify, it does have automatic climate control. I already switched out the ECC. I will go in and try to inspect and clean the climate sensor through the radio slot and take a look at the damper motor. Hopefully one of these two approaches will fix the problem. I will let you know what I find.