While my dash was out, I drove the car with the harness plugged in and my CPU went hay-wire, methinks. The horn stays on-- unplugged it for time being, the shift-up light stays on, the oil pressure gauge does not read any pressure, and my driving lights fuse blows even with the headlight switch unplugged. I don't think I have a short anywhere. So is this all related to a bad CPU?

PJ

 

no, almost non of your described problems would be related to the CPU.

Only the Horn, which I would bet was just a shorted wire on the streering wheel.

But perhaps you pinched a harness when you had yoru dash out?