P38 2.5 Diesel 1998 blend motor confusion

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madbrit

madbrit

Active Member
Posts
169
Location
Bath UK
I have replaced all the potentiometers in my blend motors BUT as they were taken out WAY before Christmas I cant remember what blend motor goes where.

There are three motors as you all know, with the main cables coloured BLUE, BLUE and GREY

I did make a note of which went where and even take photos as I normally do, but I have lost the photos and the note is also lost, can anyone help.

I Think the Blues are the blend motors, while the grey is the one distribution motor on top of the right blend motor
Any help please

Thanks
 
The motors are all the same and will calibrate themselves with a full motion check when you turn the ignition on, it at least mine did
95% sure if you look at the connector with the tab at the top, pin 1 is white. The last pin on the top row belongs to the motor for the right hand side blend flap
 
Ok, found this out, and some wiring diagrams are confusing in the pin numbers, that's what threw me
The correct pin numbers are with the catch facing you and looking down on the wire side

9 10 11 12 13 14 15 16

1,2 3 4 5 6 7 8

1= S Grey
2= RB Red Black
3= Blank Not Used
4= S Grey
5= RB Red Black
6= B Black
7=W White
8= W White
9= N Brown
10= B Black
11= N Brown
12= B Black
13= RB Red Black
14=S Grey
15= W White
16= N Brown

LEFT Blend Motor Is 12,11,8,13,14
Right Blend Motor Is 10, 9, 7, 5, 1
Distribution Motor Is 6,16,15, 2, 4

Hope This Helps anyone

MaDbRit
 
Last edited:
I have a fault come up on the nanocom evolution, it reads
right blend motor potentiometer feed back circuit has a fault

So I swapped out the right blend motor with another one, cleared the fault, ..... same fault came up, so I put another blend motor in there, cleared the fault. same fault.....

took out all the blend motors from the circuit, same fault, even though there no blend motors in the circuit (I have cut all the wires, so plugs is in)

Desperate I changed the hevac control panel, mput all blend motors back in ... same fault came up ??

I think I read somewhere that there is a wire from the speedo unit, that affects the hevac unit, send power to it, or something like that

I have tested all the blend motors for movement with a 9v battery, they all move that way
Any one any ideas
 
madbrit said:
I have a fault come up on the nanocom evolution, it reads
right blend motor potentiometer feed back circuit has a fault

So I swapped out the right blend motor with another one, cleared the fault, ..... same fault came up, so I put another blend motor in there, cleared the fault. same fault.....

took out all the blend motors from the circuit, same fault, even though there no blend motors in the circuit (I have cut all the wires, so plugs is in)

Desperate I changed the hevac control panel, mput all blend motors back in ... same fault came up ??

I think I read somewhere that there is a wire from the speedo unit, that affects the hevac unit, send power to it, or something like that

I have tested all the blend motors for movement with a 9v battery, they all move that way
Any one any ideas
Click to expand...

Don't the motors have to be put in with a certain alignment? Might be put of expected range? Sure I remember Wammers mentioning something.
 
I give up. Spent 4 days on this. So putting switches in There no Rhyme or reason to this everything checked out power where there should be power new potentiometer is I control board from a car I know is working and it still doesn’t work so I’m putting three switches in
 
I need this car on the road. As my other one is going into the shop to investigate overheating. I suspect head gasket. As tney were only done a few months ago he is ha big or bavk. He se I need this on the road ASAP.
I agree with your comment but I’m only giving up for now what was your problem in the end with the blind motors
 
The passenger one was just stuck, connected a 9v battery to get it moving and it's been fine ever since the drivers one has a dead potentiometer, soldered a new one in but it still didn't work, i think the motor was out of range so it wasn't taking the expected current, replaced it and that fixed the issue
 
Few years ago I had an issue with the sockets inside the 16-way blend motor connector. Cleaned the contacts several times, but still got the fault in Nanocom. Then I squeezed the socket contacts a bit, and the fault was resolved . . . . . until couple of months ago when it re-appeared.

Strangely on 1 or 2 days out of the month the book symbol disappears for few hours, but always comes back next time the car is started.
 
I have tried 6 different motors on 3 different positions. Even new pots nothing. 2 different control panels. Nothing. Power getting to board in pins 1 2 3 and 8 on white plug. I just don’t know where to go from here
 
Do you see feedback voltage if you move them manually with Nanocom ?

Screenshot 2021-08-19 at 15.03.51.png
 
madbrit said:
I need this car on the road. As my other one is going into the shop to investigate overheating. I suspect head gasket. As tney were only done a few months ago he is ha big or bavk. He se I need this on the road ASAP.
I agree with your comment but I’m only giving up for now what was your problem in the end with the blind motors
Click to expand...
That's easy for you to say.:eek:;):rolleyes:
 
  1. Did you make sure the gears were all properly lined up ?
  2. Also were the potentiometers exact same type ? (10K-ohm Linear & ideally the slot should match the original)
FYI, if you power them from HEVAC while not installed onto the heater box, the HEVAC drives them to one end & stops. You have to power cycle the HEVAC and then re-calibrate them. Ideally fit them to a spare heater box for testing.
 
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