Tach Question .

[BadJoey]

I am putting a 70 Challenger back together . I never had it when it ran . If I'm not mistaking the tach wire is gray with a black tracer .The question is where dose it hook up . the poss post on the coil ? 

[the_engineers]

Most tachs hook to the negative post on coil.  I'll see if I can find my FSM.

[MEK-Dangerfield]

It hooks up to the "-" side of the coil. If you put more than 5 Volts on that wire, you will cook your tach.   

[BadJoey]

Glad I asked . Than k you much guys .

[BadJoey]

BOY . This really is GOOD FRIDAY ! The guy I bought the car from 30 years ago told me the tach didn't work . Well it WORKS now . Happy Day !

[MEK-Dangerfield]

Way to go!!   

Next, let's hope the tack is reasonably accurate.   

[BP23G0B]

BOY . This really is GOOD FRIDAY ! The guy I bought the car from 30 years ago told me the tach didn't work . Well it WORKS now . Happy Day !

For 15 years I've thought my tach was toasted.  After reading a thread about putting the signal wire on the "-" side of the coil, I decided to double check to see if mine was wired correctly.  I found it was hooked to the "+" side of the coil.  It sprang to life last month after I moved that one wire.    
If only more problems were that simple...

[CUDA JAS]

Yeah I know what you mean.

I drove my car with no tach for three summers after I got it. 

When I pulled out the gauges to do dome work, I found the dork that put in the rallye guages did not bother to hook up the tach.