My battery died and I had to be jumped then i replaced the battery and after that my tach would not work. the fuses in the fuse panel are good.
HHHHHHHHHEEEEEEEEEEEELLLLLLLLLLLLLLPPPPPPPPPP.

 

Check your trailing coil and make sure they didn't knock off the lead from the tach that goes to there.

 

after i did my rebuild, my tac also stoped working..

which is the lead , from the trailing coil, that goes to the tac? where should it be?

 

Each coil has two ears on the side for the low voltage wires and the center connection for the thick high voltage wire.

The leading coil on 1981-1985 cars has one wire on each low voltage ear.

The trailing coil has two on one and one on the other.

It's different on the 1979 and 1980 models as the tach runs off the leading coil. For that, you must follow the diagrams in the back of the Haynes manual.

 

Also, make sure that your trailing ignitor is still good. No tach was the only symptom I had of a bad ignitor. You won't even feel the difference when driving it. Hope this helps.

 

i didnot realise that the 79-80's tac ran off of the leading coil.

i will check those wires soon, but will not have a chance to see if it works until i get my car running again. (it craped on me yesterday).

 

first, i'd make sure everything is plugged in correctly (ignition coils, plug wires, etc). then i'd use a timing light to make sure both plug wires between the coils and the dizzy are carrying current. if one isn't, you've narrowed it down to one of two things - the coil on that wire, or the ignitor associated with it.

i'd swap in a known-good coil to see if it fixes your problem. if not, i'd move onto the ignitors. they're attached to the neck of the dizzy leading on front by the fan, trailing under the alt.