That sounds like you have a power problem. Check the chassis to engine and battery grounds. Also check that the dash grounds are okay. The main harness plugs through the flywheel can get corroded as well and cause intermittent problems.
Probably the easiest way would be to just start in one corner and pull/tug/wiggle each section of the harness until you find the fault. Unless you own or can get a signal tracer. Those make it much easier, but they are usually not real cheap.
Monday, May 15th, 2017 AT 11:06 AM