Jumpin' Jack Tach

[Desert Driver]

Two years ago I installed a new Stewart Warner Tach (#82163) and it jumped all over the place. Took the car to three different mechanics who worked on the distributor...changed this, added that, lubed it, etc. Nada...except for a bunch of bills. So I called the SW tech dept and was put in touch with a tachometer specialist. Seems the SW tachometer doesn't much care for my HEI distributor and jumps. He said their current production line has a different circuitry to address that issue. The solution to my problem was quite simple: install a 1/2 watt 1000 ohm resistor inline. Voila...no more jumping and rock steady readings! My cost: approx $7.00 for a 100 pack of these resistors (no more Radio Shack, so hello Amazon). If you have a jumper, by all means contact the tach maker's tech support. And if you need a dozen or so of these resistors, contact me!

[adamderosa]

Excellent! Glad you found a solution and thanks for sharing the information!