alien heater temp control servo motor - 88 MKIII

[syty1]

I have only cold air output from the heater regardless of the temp setting (up to 85). The water control valve is working properly and the 'out' pipe on the drivers side is hot.
I've read all the threads I could find here, and have not found any solution, nor a similar issue.

The troubleshooting in TRSM shows how to test/adjust the servo motor if all the above checks out. My problem is that the 'guide plate' shown in the TRSM looks Nothing like mine...see pic. Does anyone know how to check the position of this thing?



Click on the image for a large view.

 

[syty1]

Well, at least I don't feel so bad...45 people have viewed this and nobody seems to know why it's different / how to adjust it.

 

[3p141592654]

Yeah, that's a tough one. Most common failure on those components is the internal position potentiometers. Typical failure mode is hunting of the servo. Do you see that behavior by observing the control arms?

Since the parts are discontinued, your best bet is to pull them apart and rework them. There is a writeup somewhere by supradupra on how to do it.

Found the link

http://www.clickdesign.co.uk/supradupra/html/climate_control.html

Strangely, his looks a lot like the picture, and not like yours.

 

[syty1]

Yes, strange indeed!
Thanks for the link....got me pointed in the right direction.