Help tracking down correct blend motor.

I have a LDH p38. I am only getting heat out of the left side vents (see picture). but the right side gets both heat and ice cold air.



I bought replacement motors awhile ago just in case this ever happened but I don't know which motor controls those vents. I asked a local shop and he said its the blend motor on the opposite side (which would be my glove box). I wanted to ask you guys before I started pulling stuff apart.

There are two temperature blend motors L/H (drivers side in your case) and R/H passenger side, lower of the two at that side. And a distribution motor upper motor R/H side. The R/H blend motor and the distribution motor are on your passenger side and the blend motor that controls hot or cold to the vents you marked, is the L/H blend motor on the drivers side.

wammers said:

There are two temperature blend motors L/H (drivers side in your case) and R/H passenger side, lower of the two at that side. And a distribution motor upper motor R/H side. The R/H blend motor and the distribution motor are on your passenger side and the blend motor that controls hot or cold to the vents you marked, is the L/H blend motor on the drivers side.

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Thank you very much.

lilweazel said:

Thank you very much.

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By the way adjust your hand brake it's pulling up to far. Should be hard on in three clicks.

wammers said:

By the way adjust your hand brake it's pulling up to far. Should be hard on in three clicks.

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Thanks but that's not my car. Just googled "p38 interior" and that came up

lilweazel said:

Thanks but that's not my car. Just googled "p38 interior" and that came up

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Lucky you found a photo with the correct vents marked up.

Just an update on this. Turns out its not the blend motor. Before I took apart everything to replace the blend motor I wanted to see if I could supply power to the cable to see if it was actually the motor having the problem or something else like the HVAC control unit. If you take out the HVAC unit and undo the cable on the left side closest to the engine you can supply power to two pins you can manually active the doors. I just used a 9V and it seemed to work fine moving them. Pins 9 and 10 are for the right blend door 11 and 12 are the left blend door and 6 and 16 are the distribution servo. I applied + and - to 11 and 12 (one way closes, one way opens) and I got cold air! What does mean? The control unit is not sending a signal to the doors and needs to be swapped, not the blend door.

You didn't say how long you've had the car, how long the fault has been there and whether you have the cheque book symbol on the HEVAC. If you've got the cheque book then a diagnostics session is in order with a fault clearance.The relevant flap might have jammed, stopped the motor and caused a conflict with the HEVAC. If no book symbol then check those outputs from the HEVAC with a voltmeter.
It could even be as simple as the plug not having been replaced firmly from a previous repair in that area.

Quick question, I need to buy a replacement distribution blend motor and there is a company on the bay that offer refurbed individual units. Are they all the same?

stjohnsmythe said:

Quick question, I need to buy a replacement distribution blend motor and there is a company on the bay that offer refurbed individual units. Are they all the same?

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Yes. Usual problem with distribution flaps are they tighten up. Check that the quadrant is free on it's pivot. Thing with gear teeth on it that the motor drives, a squirt of spray grease behind the gears driving the flaps will also help.

wammers said:

Yes. Usual problem with ditribution flats are they tighten up. Check that the quadrant if free on it's pivot. Thing with gear teeth on it that the motor drives, a squirt of spray grease behind the gears driving the flaps will also help.

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Cheers, I'll check that.

Already used a Nanocom on it but doesn't clear the fault.

dogsbody said:

You didn't say how long you've had the car, how long the fault has been there and whether you have the cheque book symbol on the HEVAC. If you've got the cheque book then a diagnostics session is in order with a fault clearance.The relevant flap might have jammed, stopped the motor and caused a conflict with the HEVAC. If no book symbol then check those outputs from the HEVAC with a voltmeter.
It could even be as simple as the plug not having been replaced firmly from a previous repair in that area.

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5+ years. I've always had the book symbol off and on since I got it but everything worked perfectly, despite that fact. Cold A/C in the summer, heat in the winter, climate zones working as they should. The A/C thing happened recently. I wanted to try something besides going through the hassle of getting to the blend door to see if anything else was the culprit. I already reseated the plug many times and it wasn't the issue. Some how jump starting the motor with the 9V reset something now it works fine. I just wanted to share how I fixed it so someone else might give it a try if they are experiencing the same issue.