I recently purchased a 93 Mustang GT. The tachometer is at 0 when I turn the
key on. After I start the engine, it is normal, at about 900 rpms, and after
5 seconds it moves up to 3500 rpms. It stays there unless I rev the engine
past 3.5k or if i use my power windows, hazzards, A/C, etc. It jumps around
erratically when turning pretty much anything electronic off or on.
Anyone know what might be going on here? I'd be greatfull for any help you