Help with 95 neon electrical problems?

This car has ~360k miles on it and recently had the engine replaced. With the old engine it was almost undriveable due to the wiring harness falling apart so badly. It now has the wiring harness from another 95 neon with much lower mileage and it runs fine. But, sometimes the gauge cluster (mainly the tach and temp gauge) doesn't work when you start it, but if you turn it on and off 10 or so times it seems to work normally. The biggest problem with this is when the gauge cluster isnt working right, the radiator fan doesnt work either. Any ideas?

With that many miles on it, I'd have to wonder if the ignition switch has a bad contact.

If its just the cluster not working, the most likely cause is cracked solder joints on the printed circuit. If you have a phillips and some torx screwdrivers, a small soldering iron and just a tiny bit of ability, its cake. There are two banks of pins that plug into the dash harness, and they crack. Grab the top of the dash pad and yank up, undo the 4 screws holding the cluster in, find a clean table and remove all the screws from the back side of the cluster, pull the printed circuit and solder.

Edit: Sorry, didn't read the part about the fan. That year have a relay triggered by the ecu, which decides when to turn the fan on based on engine temp or A/C request. Can't see the dash causing that...

Idk if the fan is related or not, the car sat for years with no engine, and it had other problems before (mainly the injector harness was falling apart), but not the problems it has now.

Hate to be nitpicky on semantics, but as a Neon owner i have to clarify that when dealing with dash plastics you never YANK anything, unless you are in the 80% of owners where everything is broke all to hell already anyway.

Actually other than the paint (faded and peeling nyg), its mostly still in pretty good shape for the amount of miles it has.