Heater Blower stopped working...

[mikeatfhc]

Hi all...

I did perform numerous searches on this problem and I think I am the first to pose a blower-out problem.

I need help diagnosing where the problem lies with my 1997. The heater/AC blower stopped working just as our local temperatures have started to rise - go figure.

I have pulled the blower to check it's operation - and not knowing the exact voltages it required I just crossed my fingers and applied 12 volts - it spins fine. I then checked for voltage at the connector to the blower and set the climate controls to varing positions to see if I got any voltage to the blower itself - very, very little voltage was making its way to the blower to get it to spin. On the order of millivolts.

So to spend less and try it - I bought a used ballaster resistor and installed to see if the problem lay there... nope. Still no voltage to the fan. I did check the connections to the back of the climate control to see if any broke or weren't seated properly and saw nothing unusual. I will note that the fan speed control on the climate control unit itself has been acting strangely - the led bar guide tends to 'drift' up and down on occaision, but it didn't seem to affect the blower speed itself.

Before I go off and buy a used climate control unit somewhere - Can anyone give me some ideas on what to check next? Also is there anything I should be on the lookout for when purchasing a used climate control unit?

[mikeatfhc]

Fuses are all good... anyone?

[Loren]

Find someone with a PST2 or PIWIS tester - they can run some tests to check the HVAC out.

I'm in Roseville and I have both.

[mikeatfhc]

Find someone with a PST2 or PIWIS tester - they can run some tests to check the HVAC out.

I'm in Roseville and I have both.

I was hoping you would chime in Loren. Sending a PM, thanks a bunch, mike.

[mikeatfhc]

:D I thought I'd provide an update and a very public thank you to Loren.

I drove up to Loren's house last week - he pull's out his PST2 running on a laptop, copies pages from the factory manuals, opens the car door and hooks the magic box up to my car's data port - ALA Matrix - style. Runs the PST2 through all of the car's systems.

We discover no voltage to the fan blower. We then start going through the checklists from the factory manuals. About step 8 we recognize no voltage on the blower relay pin 87 - it should be hot. We begin to suspect there might be a broken wire behind the fuse block panel... I was ready to tear it all apart right there... then Loren's bit of inspiration... let's try switching relays. So he looks up a relay not critical to operation of the car - block 10 the fan, we switch it for the suspect relay in block 18 the blower. (they wre the same types of relays) Like magic the blower fan comes to life!

I felt kinda stupid having Loren spend part of his Saturday helping me identify something I should have found myself.

So I posted this for the archives and to thank Loren for his dedication helping other Porsche owners in their time of need, no matter how stupid they are. :huh:

The moral of the story is this... don't go buying parts trying to fix a problem (I bought a used ballast resister and a used AC control unit for no good reason) AND usually the problem is a simple fix, not the most complicated one.

Edited June 15, 2009 by mikeatfhc

[Loren]

:thankyou: