99 S70 Pass side blows heat -AC works fine on driver side

welovenaples · Post by **welovenaples** » 20 Aug 2014, 13:15

View the forums and found similar issues. not sure why AC seems fine on drivers side, but blows heat on passenger side (top to bottom).

Post by **scot850** » 20 Aug 2014, 14:31

Do you have ECC or cable opperated? If it is ECC it could be one of the servo motors that has failed, or sometimes the plastic square that the servo shaft drive fits into cracks so the motor turns but the shaft doesn't. If you replace the motor you may have to have the system re-calibrated. Someone more knowledgeable may tell you how to do that. If the shaft is split, you can use a small clamp to squeeze it to work again. I remember on the 850 you could buy a replacement shaft for $15 or so, and it could be replaced without removing the dash. Do check that the offending shaft has not stuck and moves freely. The 850 flap I replaced had stuck.

Neil.

Post by **rspi** » 21 Aug 2014, 04:48

Full flow heater core, air flow, duct system oper…:

welovenaples · Post by **welovenaples** » 21 Aug 2014, 14:06

Thanks for the assist. I believe I have ECC. Are the servo motors easy to replace without removing the dash?

Post by **abscate** » 21 Aug 2014, 14:11

There is a mid 99 model year break where the ECC goes from 4 motors to three. I think the 4 motor passenger blend door is reachable from under the dash. The three motor one like mine is tough.

Tone · Post by **Tone** » 11 Nov 2017, 13:43

scot850 wrote: ↑20 Aug 2014, 14:31 Do you have ECC or cable opperated? If it is ECC it could be one of the servo motors that has failed, or sometimes the plastic square that the servo shaft drive fits into cracks so the motor turns but the shaft doesn't. If you replace the motor you may have to have the system re-calibrated. Someone more knowledgeable may tell you how to do that. If the shaft is split, you can use a small clamp to squeeze it to work again. I remember on the 850 you could buy a replacement shaft for $15 or so, and it could be replaced without removing the dash. Do check that the offending shaft has not stuck and moves freely. The 850 flap I replaced had stuck.

Neil.

Hello I posted about similar issue but for a 2005 XC70 Cross Country I believe my driver side temperature control is some how stuck on cold but passenger side blows heat perfectly do you think I have the same issue as this guy or is it completely different for my mod

Tone · Post by **Tone** » 11 Nov 2017, 13:46

Model year any info on this situation would be greatly appreciated thank
Tone

Post by **scot850** » 11 Nov 2017, 17:13

Different system, I have no idea how the P2 system works.

Neil.

Post by **abscate** » 12 Nov 2017, 14:28

Different system but same principles...full flow through AC evaporator, then diverted to vents , the air mixed with heat air to achieve temperature left and right. Failure on one side is that side blend door.

I’ve never gotten deep into a P2 climate system, tone. End of knowledge.

Post by **wizechatmgr** » 13 Nov 2017, 04:26

On the P2 VIDA can read back to you the current ECC desired temp settings as it believes they've been selected. It can also show you the perceived position of the dampers. If you see all 0's on either then the analog to digital converter chip in it has typically blown.