90 Corolla wiring Issue

I have purchased a 1990 Toyota Corolla for my son and have installed a new stereo, subs, and AMP. I cheated and wired the AMP to the rear defrost lines since they were already in the trunk, have a 15 Amp fuse, and the rear defrost had a broken trace in it anyways. My question is this: I believe that the rear defrost on these early 90's cars used a relay with built in timer function. This would allow the rear defrost to run for say 10 minutes and then need to be reset to run again. Does anyone know where this relay is and if I can defeat the 10 minute timer. I have been tracing under the dash and haven't buzzed it out yet. I am only assuming that there will be a timer and I haven't tried the circuit in real life as the car won't be put all back together until wednesday. Thanks if you have any wiring diagrams or helpful insight.

DO NOT use the defroster power line. there is no way that they can supply enough power to your amp. Go buy an amp wire kit from ebay for about 10-20 bucks. They come with the RCA interconnnects, power, ground, remote turn on,  and all the wire ends and fuse.  You prolly need 8 awg for your amp if its smaller than about 800 watts.

Buy this or one like it http:///.com/dll?ViewItem&item=1372709993 I think Walmart even has em.

I concur, you are going to experience a LOT of problems when the defroster and amp are running simultaniously.   In fact I am suprised the amp turns on without blowing the fuse in the box. 

Best Buy and Circuit City also will sell you a amp install kit.  It is worth the time to run the wires.

Good luck.

Craig