Heater control and Bently [84 5000]

[Ameer Antar <ameer.a.antar@uconn.edu>]

I just joined the list. I have a problem with my heating system. I've been 
told many times to get a Bently, but I can't afford the $100+ bucks for a 
new edition and I can't seem to find anyone who has an old edition [single 
volume] that they have an extra of. If there's anyone who has one for a 
reasonable price, I'm interested. Now for my problem:

I bought an 84 5k turbo [non-quattro] for $500. When I got it, the A/C head 
control unit display was intermittent. I could still use the buttons to 
change from say economy to defrost even without the display working. I 
figured it was loose wires, but I checked them all with no luck. Now the 
display never comes on, and I can't dial in any settings. No heat and it is 
cold in CT! I opened the head unit looking for loose wires or bad 
components, but everything was perfect. I even resoldered all the joints. 
There may be a bad transistor or chip but I can't tell.The blower motor 
works fine when I put 12v across it, so the motor is fine, but I still 
can't get the system to work at all. I was told it could be the programmer 
or the blower motor controller. I looked at these components and they seem 
to LOOK fine. What usually goes bad in situations where this absolutely no 
display on the head unit? I would think I had a bad head unit, but maybe 
the head unit display requires the programmer and blower motor control to 
work. What test could I do on the system to try and narrow down my 
possibilities? I can probably get these parts from salvage yards, but I'd 
like to spend my money on what I abs. NEED to, which I realize is hard to 
do on these cars.
Also, some more info. When I got the car it would always put out hot air. 
The programmer usually controlled the vac. valves correctly, but 
sluggishly, but mainly had problems moving the lever which controlled the 
heat level. You could manually push the lever over to cold sometimes, but 
other times it would not budge. I took off the programmer and the motor 
assembly. The gears inside look fine as well as the motor and brushes. 
However it was near impossible to move the gears using the lever, but if 
you turned the motor manually the lever slowly turned with no resistance. 
Maybe it's like that due to all the gear ratios. The weird thing is that 
the motor is intermittent. When I applied 9V across the motor directly it 
wouldn't always run. Coaxing it doesn't usually help. There was sparks 
across the terminals so maybe there is a short, but when I opened the case, 
the brushes and commutator look fine, I think. Any tips on this assembly or 
should I just get a salvage unit and replace the motor?
Thank you very much for taking your time out to read this. Any help is much 
appreciated.


a m e e r a n t a r

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