The same '04 Cavalier with the Trac problem. Nothing like having almost all the dash warning lights come on..
First found a blown fuse in the fuse/relay box under the hood. Replaced fuse and it blows again instantly. Meanwhile A/C keeps cycling on and off about every 5 -10 secs. Strange odor reported from driver before the car overheated and the dash lit up. Tested the fan relay and it checks out Ok. Tested resistance in cooling fan motor and it's way off.
That funny smell was the fan motor going bye-bye!
Replaced cooling fan motor. Fan now comes on when A/C is turned on. A/C stays on with no more cycling! With A/C off the fan comes on when coolant hits around 200. Also noticed the cap on the radiator overflow jug wouldn't tighten down all the way so replaced that too.
Just hope this helps someone.