The archives are pretty unclear about its position, its function and part number. this is specifically for a 2000 1.8t, your setup may be different.

Symptoms of failure:
What doesnt work:
-no heat, the blower isnt working. but the console does.
-no turn signals, but parking lights work
-no fogs
-no boost gauge lighting (directly wired to 75X)
-no wipers

The only DTC vag-com reported during a full scan, was that of the climate control unit and the blower "not responding". not very helpful.

At first i thought maybe the nut came off the 75X post, no luck, i dropped the knee bolster at lunch, everything is secure. Also I checked every fuse 25Amp and greater, even the 40 and 50 under the relays. all are ok.

What works:

-heated seats
-interior lights
-stereo (audi symphony)
-hi and low beams

The load reduction relay is in position #2 under the dash, its NOT in the ecu box.
position #2 is the second relay from the left in this pic(marked "213"):



To change the relay you need to drop the driver's side knee bolster, as written up here. There are (4) 8mm hex head screws, two behind trim pieces, one behind the fuse panel, and one down low above the gas pedal.

Part numbers:
443 951 253J (BLACK MARKED "213"), is what was shipped with the car

Superceded by:
8D0 951 253 (GREY MARKED "370"), is the replacement part

Iit cost $39 from a VW dealership, its probably cheaper online.