TACH Problems help
 

OK I wired up the tach, one wire to dist. - one wire to the fuse panel( marked ing. unfused. When I crank it up the tach will move with the engine rpms but at I think much lower value, also at idle the tach read o. Do I just need to adjust it with the screw in the back? :banghead: :banghead: :banghead:

Did you conect a ground wire?

I was thinking it was grounded by the ground wire in the harness. But I did try to ground the thrid prong on the back to a good chasis ground.,

Need a little more info. Is it an aftermarket tach or a stock tach? V8 or 6 cyl? I'm not saying I can answer all your questions, but I may be able to help.

If it's an aftermarket,check to see that it is set to the proper cylinder setting.4,6,8 cyl.I bet that's the problem.Some stock tachs have this setting too.
Prolly on the back,may have to remove the cover to get to it

Stock tach, new goodwrench performance deluxe 350. It came with dist. wires and plugs. HEI dist,

If the tach is an original 6 cyl tach, it'll read odd, but I think it should read high :confused: From what I've gathered, there's an adjustment screw on the back of a stock tach that you can mess around with. Use a known good tach of some sort, designed for a V8, and adjust your stock tach accordingly. Best of luck.

I've seen a stock one act like this. I'd rev the sucker to about 3500 RPM and hold it, and the needle would slowly rise to about 1000 RPM.
We chucked it and slapped in an aftermarket one.

Thanks guys for the help. Iguess I'll play with the adjustments and see what happens. Just made the normal nightly run to the gro. store and the tach would move a little at normal rpm and speeds around 0-500 but when I hammer it the tach seems to read closer to what it should, but as soon as I let off the gas the tach returns quickly to 0-500 range. Maybe it needs adjusting. Thanks