F150Gearhead
New Member
Recently my tach started behaving oddly. When started it immediately jumps up to about 2,000 rpm and stays there until the engine rpm's approach that speed. At which time it does start to move along with the throttle. It varies like it should but reads about 1000 rpm higher than the actual engine rpm. At cruise speed where it should be reading about 2k it reads 3k and if you slow down it will drop back to 2k but go no further. I know that the drivetrain is functioning properly. I have had this truck for a quite a while and know how it sounds and feels at various speeds.
These tachs are pretty expensive and I was wondering if it might be possible to repair it. I know that these meter movements are electromagnetic in design and are probably not that complicated. Does anyone know of a schematic that might be useful in a repair attempt or perhaps be able to point to a component that may have failed?
I looked a bit for a possible source of induced voltage as the wiring passes very close to the coil but didn't see anything that looked abnormal.
Any thoughts, anyone?
Gearhead
These tachs are pretty expensive and I was wondering if it might be possible to repair it. I know that these meter movements are electromagnetic in design and are probably not that complicated. Does anyone know of a schematic that might be useful in a repair attempt or perhaps be able to point to a component that may have failed?
I looked a bit for a possible source of induced voltage as the wiring passes very close to the coil but didn't see anything that looked abnormal.
Any thoughts, anyone?
Gearhead