L/S heater blows cold P/S heater blows hot - '02 Seville

[COLLEEN]

On my '02 Seville, with both sides set at warmest setting on controls, driver side blows cold outside temperature, while passenger side blows hot. Any ideas?

[lothos]

I just fixed this problem on my girlfriend's 04 Monte Carlo. The problem was the "blend door actuator". It's a little motor that moves the vents and is controlled by the heater control on the dash. I read that this blend door actuator is a common failure.

It's located up under the dash. To get to it you take the kick panel thing off, it's the cover where the drivers knees go. If it's similar to the 04 Monte Carlo, it's up against the side of the heater control area under the dash.

[COLLEEN]

I just fixed this problem on my girlfriend's 04 Monte Carlo. The problem was the "blend door actuator". It's a little motor that moves the vents and is controlled by the heater control on the dash. I read that this blend door actuator is a common failure.

It's located up under the dash. To get to it you take the kick panel thing off, it's the cover where the drivers knees go. If it's similar to the 04 Monte Carlo, it's up against the side of the heater control area under the dash.

thanks for the suggestion.

If that is the problem, I suppose the fix is to replace it (if beating it with a hammer doesn't work)?

Can anyone describe more accurately the location of this part on a Seville SLS? TIA

[lothos]

thanks for the suggestion.

If that is the problem, I suppose the fix is to replace it (if beating it with a hammer doesn't work)?

Can anyone describe more accurately the location of this part on a Seville SLS? TIA

Haha yeah the fix is to replace the part. The part has gears inside with little plastic teeth that break.

Sorry I'm not more help on the part location. I'd try to describe it better but I'm not sure if they're in the same spot as the 04 Monte Carlo that I fixed.

[gone12]

replace the heater core

[KHE]

replace the heater core

The problem is clearly a mix door problem since there is hot air on one side of the car and cold air on the other side. Replacing the heater core would be a waster of time and money in this case.

Someone with a 2002 service manual should be able to post the location of the actuator. It is possible that the rod has come loose and all that is needed is to re-attach the linkage and go through the calibration procedure.

[rockfangd]

replace the heater core

The problem is clearly a mix door problem since there is hot air on one side of the car and cold air on the other side. Replacing the heater core would be a waster of time and money in this case.

Someone with a 2002 service manual should be able to post the location of the actuator. It is possible that the rod has come loose and all that is needed is to re-attach the linkage and go through the calibration procedure.

not necessarily. A heatercore could be the culprit as it is located on the passenger side and will get warm enough to feel heat on the passenger side which is closest to the heatercore, but not to the driver side. I believe one way to prove it is not the heatercore is to see if the vent on the rear of the center console has heat.

[lothos]

reading up on the issue before I fixed my gf's car, people were also saying it could be a thermostat. She was getting thermostat trouble codes so we replaced it but it wasn't the issue.

I also read that it could indeed be the heater core. We felt all of her coolant lines and they were all hot so I didn't think it was the heater core. Her heater core was new, it was replaced six months ago too.

It was said that the most likely problem was the blend door actuator though, because they're known to go bad on a whole range of GM cars from that year range.

Let me try to describe the location a little better:

Sitting in the driver seat, next to the gas pedal. To the right of the gas pedal is the side of the center console. The part is attached to that. You have to remove the "kick panel" where the driver's knees go to access it. The part is located a few inches higher than the "kick panel" attached to the center console wall.

You kind of have to lay on your back and look up to see it.

[KHE]

not necessarily. A heatercore could be the culprit as it is located on the passenger side and will get warm enough to feel heat on the passenger side which is closest to the heatercore, but not to the driver side. I believe one way to prove it is not the heatercore is to see if the vent on the rear of the center console has heat.

If the air temp. is hot on one side as reported and cold on the other side, I would not suspect a heater core. Much easier to check and replace the actuator vs. replacing or backflushing a heater core.

[Ranger]

It is somewhat common for the heater core to cause this in cars that use the sealant tabs. The residue collects in the bottom of the core and the air passing through it gets stratified. The cold bottom half goes to the drivers side and the hot upper half goes to the passengers side. It would be well worth the time to flush the core before replacing it. That said, before you do anything, pull the DTC's. A bad actuator will set a body code.

[COLLEEN]

Thanks all for the additional info. Haven't gotten around to actually fixing it yet. It's not that cold in Florida. The air on the passenger side is pretty warm, as opposed to not warm at all on the driver's side, so I think the blend door actuator is the problem. I'll attend to that, after I go through the diagnostics for a code.

[lothos]

A bad actuator will set a body code.

It didn't set a code on my gf's 2004 Monte Carlo, it might not here. Although I'm not sure if the part store code reader would pull a body code on the Chevy.