Can't get the fan motor to work on my new 89 LX. I checked the ground, it's good. I jumped power to fan, it works. Won't come on during engine running or when I turn on the AC.
the controller under the steering column is known to be junk. jumper it out and see what happens.
Many people have placed a toggle switch inline to activate it (bypassing the controller)
If you want to replace it, they are still available.
it is right behind the fusebox, and is a black box... mine went bad in my car, and i got a new one (for $80!!!) and now it works, i have some links to a hard wired fan, if you want to take that path.. send me a private message with any more questions
I replaced the relay under dash, still does not work. Someone said that there was a master relay on the right shock tower that when replaced would cure the problem.
The one on the shock tower is the later model mustang. Yours should be a black box with TRW on it. Near as can remember has 7 wires. Mine burnt out the wire connection. I wired in a relay to the board and use the realy to turn my fan one and off. But still using the board to control it. If want to do this way let me know and will scan the diagram and box. It does involve soldering and wire splicing. I prefer this method. relays are cheap compared to boards.
Also please check that relay for burnt connection. Even if it works. Would hate to see your car burn. Take a little time but might be worth it. If don't know what looks like. Let me know.
Fan motor no go on 1989 Mustang LX 2.3 
