For starters this will be a long post. Just finished changing out the AC Evaporator and Heater core on my 98 V70XC AWD. Whew...big job for DIY but learned a lot. All went fine. While charging up the AC system I noticed that I wasn't getting much cold air on the drivers side of cabin. Passenger side got really cool, 45 degrees. So after recharging the AC system I investigated what could be going on with the drivers side. I found that I had failed to connect the driver side blend motor up. (the one behind the cruise control vaccuum pod that mounts on the heater box.) Easy fix, so I thought. I hooked up the electrical connect and felt sure I was on my way.

Starting the car and AC back up, I discovered that the problem now has just reversed. I now have great cooling on the driver side and really poor (almost real warm) cooling on the passenger side. Not so easy a fix after all.. I uncovered the passenger side glove box and lower panel to check things there. The blend motor is connected ok on the passenger side.

I need to inform you that I have had the ECC Recirc/AC off lights blinking at engine start for about two years now but all has seemed to be working fine execpt that I would have to charge the AC up each spring to get it to cool for the summer. That is why I went on decided to change the evaporator out because I could not find any signs of AC leaks anywhere else (plus dealer said they were bad about going bad, and I did it myself because dealers charge was 1300 for the Evap change).

Now after joining here and reading a large number of post on AC/Heat issues it seems as though I have got the blend doors out of sync with each other now. Short of getting a dealer "recalibrate", does anyone have a good fix for getting these puppies back in sync for a DIYer?

Oh and I believe my Recirc/AC blinking lights were & are caused by the cabin temperature sensor. It was full of lint and the fan was not running in it. I did clean it out and checked the fan to make sure it would turn. I have reinstalled it but the fan in it still does not run. Anybody been sucessful in getting one of these running again?

Sorry for such a long and drawn out post.

 

Try to find an independent shop near you that can recalibrate the doors for you for cheap.

I would get a new temp sensor and run from there.

 

So Tech, did i cause it by leaving that connector off the left blend motor? Seems as though if I caused it by doing that, I could undo it reversing the steps... just a thought...

I did read on here about disconnecting the battery after 10-15 min.. and then hold the positive and negative ends together for about the same and that would clear the computers... Does that have any truth to it? Or would that loose the software???? Just trying to pick your brain Tech.....

Those temp sensor's are a bit pricey aren't they.... eEuroparts wants $135 for that pup.... They are usally the best prices I have found for things.

 

If the temp sensor is bad the codes might clear but as soon as you turn the key on codes will be back.

You can try that with the motors may and may not work.

 

Thanks for the reply Tech. Yes I figured that fault would come back if the sensor is bad. I assume that temperature bulb in the sensor is working since I never really had any problems holding a preset temperature in the car before all this. The small fan in the sensor serves to draw air over the bulb so it is always sampling. I guess that the ECC would also know if the fan is running also and if not would trigger the fault. But I'm not sure 100% on that.

Today I took the two blend motors off their mounts and made sure that the blend shudders inside the AC/Heater box are both in the same position manually. I learned that the two blend shudders only trave 1/4 turn from full open to full closed. I also learned that the all the actuator motors are all the same (4 of them; 2 AC/heat blends, 1 outside/recirculate door, & 1 defrost/bilevel/floor diverter door). I got a bit concerned after I learned that because it might have been possible that I connected the wrong connector to the left blend motor since it is pretty close to the defrost/bilevel/floor diverter door motor. So as a result I took some the dash back apart to verify that I hadn't got those two mixed up. After going through that I'm pretty sure I didn't cross those two up. The connector that I have on the d/b/f diverter motor looks where it should be as fars amount of slack in the wires. It might reach on further to attach to the left blend motor but it would a pretty good strech on the wiring and I'm sure it wouldn't be designed that way. Anyway, I'm satified that they are not crossed up.

Tomorrow I plan the put all back together while leaving the two AC/Heat blend motors off but plugged in and run the system and get both of them to same position that match the manually closed blend shudders. Then I should be able to mount them back up and they should be sync with each other again. My calculations/figuring/best guess... fully closed blend shudders will result in full hot settings. It's a 50/50 right or wrong.

I know you probably thinking I'm going to a whole lot of trouble when a simple recalibration at a shop will do it so much eaiser. Well I'm one that just has to know how things really work and want to understand it. Thanks for sharing your experience with us. Not everyone likes to do that.

 

I hope it all goes well.

 

All has gone well . Friday I was sucessful in getting the blend motors in sync with each other as I described in my eairler post. My 50/50 guess above also turned out to be correct. Blend doors rotated down result in full hot position. The hardest part of all this is one of the three screws that mount the blend motors to the climate control box is really hard to get out and back in because you can only see it with a mirror and flashlight. If you drop it in the process it usually falls into the center console area (hard to retrieve if your dash is all together). Thought I had a bad blend motor at first becasue the passenger side actuator would not respond. Made sure power was at the connector by switching actuators and it worked. Did a continuity check on the actuator and showed that the motor was shorted. I took the actuator apart and once inside I pulled the circuit board out (motor is mounted on the bottom of the circuit board) and the motor itself checked good (no short). There was a lot of lithium grease on two carbon strips that the positioning contacts rides on. Power to the motor has to flow through those carbon strips at various positions depending on what temperature the climate control unit is asking for. Anyway, all I did was clean up the execss grease there and put it back together and the actuator work then. Another long post to say all went well.

So as a result, I have learned that you can do a so called "recalibration" of the climate control system to get the blend actuators back in sync with each other without going to the dealer to get it done. I hope this is of some help to anyone in the future and I want to thank everyone that have contributed here.

Great forum!

 

Glad all went good. Congrats!

 

Thanks Tech. Yes all execpt the cabin temp sensor fan still will not run. The motor is not shorted. The windings in the motor continuity check good with .67 ohms. Can't see anything burnt or shorted on the circuit board of the sensor. The temp bulb portion of the sensor is working because in auto the system controls the temperature to the settings selected. I will follow up on it later... as for now.. its working as it always has in the past. I can deal with the flashing recirc/ac off lights for 20 seconds at each start.

 

Man. I can NOT get that passenger side blend motor out. Is there anything that I can rip out of the car to make it easier to get to? I can only get one screw out. If not, are there specific tools that you used? The only thing I can think to try to find is a flexible-shaft flex bit handle. I can't seem to find one that's delicate and slender enough. I'm at wit's end.

 

I was able to get to it by removing the glove compartment door and container box. I don't recall using a flex shaft but could have. It has been almost 7 years ago now and you have to remember I had just finished removing the entire dashboard from the car to change out the A/C evaporator. I will try and pull up a picture for you.

You can see the blend motor pretty well and get to it with the glove box assembly removed.