Interior blower not working, no heat or AC
 

The car is a 2004 Boxster S. AC and air worked perfectly yesterday and now when I turn on the air I can hear the vents opening but the blower does not turn on. Everything seems to work fine on the control unit. The blower does not come no matter what the setting, (manual, auto, AC on or off). I checked the fuses and they are good. I switched a few relays around and no luck. I also saw a few posts about the key ignition position but it doesn't seem to make a difference. The wipers work fine. Anything else I can check before I have to pull the motor? And what is the right way to test the motor?

Any other electrical gremlins? The electrical portion of the ignition switch can cause all types of oddities as they wear out. What year and mileage?

Move the relay above the fuses box, it is prone to move a little.

You don't want to have to access that motor unless you ABSOLUTELY HAVE too. Exhaust all electrical possibilities first

No, everything else seems to be working fine. The control unit even seems to be controlling the air vents and I can hear the AC compressor kick on when it is selected.

It has about 110,000 miles on it

Explain what you mean a little more. ... you mean like wiggle the relays? I pulled a few of them and reinstalled them. I also switched a few around to see if maybe one was bad but to no avail.

Yes I wiggled mine when the blower wasn't runing and it worked, I did that after having pulled everything
out (of course), there is also a resistor located in the fan casing

This has been getting very frustrating. After searching around some more I found some methods of testing the circuit. One of the methods was to check slot 87 of relay 18 which should have battery voltage with the key in the on position. It does not. Also there was a test for the control unit by removing the C connector and testing some pins. Apparently I have some sort of wiring variation and do not have the C or A connector. I scoured the area looking for a connector that may have been disconnected but it just does not exist. Any ideas of where to go from here?

Here is the latest update. All the possible fuses have been pulled and tested as well as the fuse block itself. Relays 18 and 9 were changed out for other relays and still nothing works. Also the relay block itself gets 12V at terminal 30 at both position 18 and 9. The next step would be testing connector C on the control unit however this does not exist and I have searched my wiring harness but there are no extra connectors. My thought is to skip that step and test the fan resistor. Where is this located and can it be tested?

The problem was found, it was a faulty wire going to the blower motor. The details are at this thread.
Interior blower not working, no heat or AC - Rennlist Discussion Forums
The 2004 Boxster S apparently has a very different wiring setup than the diagrams listed in the repair manual.