First of all, check fuses # 9 and 17 on the left side of the dash board. In particular, if fuse # 17 is blown, most of the warning lights, and the transmission gear indicator lights also will not work.
The least effective, most costly way to diagnose electrical problems is by blindly throwing parts at the problem, but in this case, you might want to try a different Body Computer. It talks back and forth with the instrument cluster and other computers on the car. There is a very important thing to watch out for though.
If your car has the factory-installed anti-theft system, you can safely install any used Body Computer of the correct part number. But once you do, that computer can only be used in another car with the anti-theft system. (If you borrow a computer from a friend's car that doesn't have anti-theft, you can not put his computer back in his car).
When you buy an Engine Computer or a Body Computer from the dealership, they always come programmed for cars without anti-theft. If your car has anti-theft, the computer you install will learn from the other computer that anti-theft is on the car, and it will self-program itself for that system. That upgrade programming can not be undone. That's why those computers can't be put back in a donor car it was borrowed from.
If you borrow your friend's non-anti-theft Body Computer, your Engine Computer will teach it to self-program to the anti-theft system. When that Body Computer is put back in your friend's car, the now upgraded Body Computer will teach his Engine Computer to also self-upgrade to the anti-theft system. Since anti-theft isn't actually on his car, the disarm signal will never come and the engine won't run. The only fix then is to replace both computers at the same time. If only one is replaced, it will again self-upgrade from the other one.
Does that make sense?
If your car has anti-theft: * any Body Computer will work.
* any Engine Computer will work.
* do not put either computer into a car without anti-theft.
If your car doesn't have anti-theft: * you must install a Body Computer without anti-theft.
* if you mistakenly install either computer that has anti-theft programmed in, you must replace both computers at the same time, before turning on the ignition switch, or the engine won't run.
Sorry to get so long winded, but not knowing this oddball fact can lead to a lot of hassles and frustration.