I am wondering whether the stealer screwed up my heating system. A few weeks ago, the A/C wouldn't shut off, literally, even if I pulled the key out of the ignition. Thus my battery was running down every night and I needed a jump star in the morning.

So the stealer replaced the "blower controller" or something like that and everything seemed fine. then it got cold two weeks ago, and I can't get any heat out of the A/C. plenty of cold air, but no heat. even if I set the controls on HI, the fan won't come on, but if I put it on LO, the A/C blows fiercely cold.

stopped by today and they gave me the sure-we'll-take-a-look-at-it-again line but I'm wondering how likely it is that they messed up something during the last fix.

maybe it's too obscure to speculate, but I'd be curious if anyone smells a connection.

 

You need to look at the measuring blocks on HVAC using VAG-COM

 

ok thanks. next step: get vag-com :-)

 

1. With the temperature on HI, does the fan blow if you turn it up manually? For it not to, when it works for cooling, would be strange. But even on HI, the fan won't come on automatically until the controller thinks heat is available (in 2001 at least).

2. If manual fan control works and the engine is warmed up, is the air hot? If so, look into temperature readings seen by the HVAC controller (outdoor, post heater core, and calculated coolant temperatures).

3. If the air's cold, try bleeding the cooling system, especially if the coolant was changed since the heater last worked. Leave the temperature on HI. Open the screws next to the heater hose, and rev the engine to 4000 rpm several times -- it really can require that to start coolant through the heater. (You're also supposed to unplug the electric coolant pump when doing this, but if bleeding was the problem, the pump's already been run dry.)

4. If that's no good, try pulling the seventh fuse from the right in the third row from the top. That opens the heater coolant valves regardless of what the HVAC controller wants. If that starts the heat, the HVAC controller is confused -- I can't see why it would ever close those valves with the requested temperatures on HI.

Other unlikely possibilities include a kinked heater hose or a blockage in the pump/valve block for the heater.

I'll be interested to find out what it was.

Tom

 

I'm no mechanic, but it's good to hear that it might be something small rather than diastrous. Mechanic can't take me til a week from Friday, so cross your fingers for me that it doesn't get too cold befroe then...

 

i have no heat whatsoever blowing through the vents