Where does the tach get its signal from?

[Projex240]

Its from the distributor, right?

REason asking---my tach was jumping and going haywire today fro about 20 minutes. I think its becasue teh connections I made at teh ecu fro my AFC may have become hot and loosened. The afc shows no sign of jumping rpms--just the tach itself.

Thanks,

Josh

[Projex240]

update---i dont thinkits anything to do with where the tach gets its signal from. I checked th afc--and its still reading correctly. So--this means that the signal coming fro the dist to the ecu is still right. The connections at the afc splices are solid, but the tach craps out when i rev to 3300. It starts to jump up and down like its flipping out--and i mean like fast. Not like revving it self--like bouncing like a retard fast. I think its the tach gauge itself--i think replacing the cluster will fix the prob---im about to put a black faced cluster in--i think it will be a nice change from the white face gauges.

-Josh

BTW--just in case this thing doesnt work (the new cluster), what else could it be?!

Id be stumped if this doesnt ifx it.

[Structure240sx]

i have a black gauge cluster for sale if you want.

you may not need it tho. i was having the problem of the tach needle jumpin around a couple hundred rpms higher up in 4th and 5th gear. finally i realized that it wasnt jumping on the safc. so i wasnt too worried and was goin to swap it with the above gauge cluster. one day tho it jsut started working fine. weird. btw in 5th gear it would start moving at like 3500rpms

[im two techno]

On your 96 the RPM's come from the speed sensor on the trans

[klattr1]

On your 96 the RPM's come from the speed sensor on the trans

just read your statement again. That makes no sense whatsoever.