90 b2, is the tach computer controlled?

[nutpantz]

90 b2 2.9 5sp, is the tach computer controlled or is there a tach wire to the distributor?
My tach reading keeps changing (it might be doubled)...
Sign of my computer going to die ? or need a new tach.

 

[shane96ranger]

It runs off of the ignition coil.

According to the tech library it is a tan wire with a yellow stripe coming off the coil:

1990-1992 and some 1993 2.9L -- Tach test on coil (Tan with Yellow Stripe)

 

[nutpantz]

Thank you I'll hunt that wire down and check it..