Just guessing, but could be the box that controls the amount of time the intercooler(I/C) water spray runs for.
Test by unplugging it and pressing the I/C Water Spray button and seeing what happens then try again with it plugged in.
p.s. If you have the bonnet up you can do it yourself

 

Subaru Impreza WRX Type RA
1994 Import, Standard other than Stainless 6" Straight through exhaust (i think!) and Foam air filter element.

I had a problem with the boost valve cutting out and high boost a few days ago and now the boost valve has been replaced, pipes cleaned e.t.c it seems okay but I also found a big relay which was not plugged in! It was under the dash by your feet and had TIMER I/C written on it. (Does anyone know what this is?) I do not know if I really needed the boost valve and did I waste my money? It also seems to boost at 1.0 bar now and I thought it used to boost at 1.2bar.....

Any ideas????????

Cheers
Scott

[This message has been edited by scoootie5 (edited 26-01-2000).]