Hevac blend motor issues

I have a recuring problem with the blend motor which controls where the air is directed.

Firstly the starting point is that I have got the air conditioning working with all the blend motors replaced etc. I have recalibrated the motors using the usual blackbox solutions kit and my laptop. Everything works well for three months and then the testbook symbol appears.

The fault comes up as failure of the feedback circuit in the blend motor. I obtained a couple of feedback potentiometers from a senior member of this forum (many thanks by the way) and replaced it. Back together and recalibrated it worked fine for three months.

Same fault and same problem again. Replaced the potentiometer again. Worked fine for (you guessed) three months.

So apart from not having any more potentiometers, I really am looking for a proper solution. I suspect that the circuit inside the Hevac unit which applies a voltage to the potentiometer is faulty and it applying a raised voltage to the potentiometer - and burning it out after tree months.

Is there anyone who can repair the Hevac unit? or do I need to buy a new one (as opposed to a second hand one)?

Thanks in anticipation.

not heard of anyone repairing Hevac units. I know that their is several different part numbers. I would get a second hand one.


http://www.rimmerbros.co.uk/Item--i-JFC102550