Bonus points to who can answer this

[catlin_cava]

If you can answer this you are a VW God.

The car- 2001 VW Jetta TDI 5peed, with AC,

The problem- when I push the air recirc button in the car it doesn't come on...HOWEVER the handbrake light will come on...

WTF?

[the caveman]

Well for the first part, if it's on defrost, recirculate doesn't work [its because you're asking the AC to dehumidify the interior].
as for the second part- if i remember the part of the harness which has the handbrake switch wiring in it runs with part of the AC wiring. I've seen a couple where the AC wires were fraying at the center console brace or was it some other metal part in the center behind the dash. Either way it was on the r/s of the HVAC controls- so maybe there is a short between those 2 circuits

[8v-of-fury]

Caveman is godd lol

[the caveman]

well, only if i'm right...

[catlin_cava]

I turn the recirc on when its on the floor setting to heat up my feet more, and I noticed the last time I used it the button was hard to push. tomorrow ill be behind the dash so I will look at the harness and see if you are God

[the caveman]

I had to remove the dashes on those couple of cars to find the problem, so good luck. Another thing which should be looked at  first [because it's way easier], is to remove the D/S under dash/knee bar and check the grounds near the steering column. Even though there is less chance for things to fail because of some poor grounds, those models were notorious for bad ground connections. The ones in the engine compartment [the ones under the battery tray], caused the most problems. I spent 2 winters just re-newing grounds, mostly gassers, but some diesels also].
remove the loops, sand, clean and put some dielectric grease on the mating surfaces.
There is a good chance  any weird electrical issue on Mk 4's can be caused by this.