P38A Blend motors & temp controls

Hi All,

Have had a search around but haven't come up with anything yet someone might know the answer though.

Took the dash out todo to replace the leaking o-ring that's been leaking for the past year and thought at the same time I would rebuild the blend motors as the passengers side is stuck on hot and the drivers side stuck on cold.

Took them out and apart nothing wrong at all, put all back together and ran through a test.

Set the passenger side to HI and the blend motor moved perfectly fine, tried the same on the drivers side but nothing happened.

I then set the drivers side to LO and it moved the passengers side blend motor!

I set the passenger side to LO and then set the drivers side to HI which in turn moved the passenger blend motor...

When putting the ignition on to let the system run through its check it opened and closed both blend motors though so I'm 100% sure the drivers I working, I just can't control it...

Has anyone come across this before?

Thanks.

The HVAC control unit has been known to loose its head .... or the temp sensors for each outlet is duff....

Check connections to the HVAC control unit for security, cleanliness and broken connections.

I would suspect the connector where the blend motors plug into the HEVAC, or somebody has replaced the motors and got the wiring wrong. Could also be the feedback potentiometers in the motors giving false readings.

Best way is to get a Nanocom on it and then test & control manually them in diagnostics.

The blend motors are fitted incorrectly.

wammers said:

The blend motors are fitted incorrectly.

Click to expand...

Fitting to the Heater incorrectly? Or wired incorrectly?

pwood999 said:

I would suspect the connector where the blend motors plug into the HEVAC, or somebody has replaced the motors and got the wiring wrong. Could also be the feedback potentiometers in the motors giving false readings.

Best way is to get a Nanocom on it and then test & control manually them in diagnostics.

Click to expand...

Have taken a look at the wiring all seems to be fine and matches up to wiring diagrams.

Will have to get my hands on a Nanocom to test them manually. To see the outcome,

stewd said:

Fitting to the Heater incorrectly? Or wired incorrectly?



Have taken a look at the wiring all seems to be fine and matches up to wiring diagrams.

Will have to get my hands on a Nanocom to test them manually. To see the outcome,

Click to expand...

More than likely transposed. L/H motor at R/H side and R/H motor at L/H side.

Forget that just reread you first post. Do you have the book symbol on the HEVAC? You need a Nanocom to read fault codes. Did you re assemble them correctly with marks on gears lined up? You can sometimes get broken or dry joints on the PC to the pot. They can also fail sometimes with a build up of carbon dust on the motor armature.