Ok so I got a tach cheap off ebay and decided to install it, hooked up ground, light, power, and the tach signal (white/pink wire) started her up....didn't work, so I tried the tach signal on the other, w/pk wire (there was 2...hum) still no worky. Tried the tan/yellow wire on driver side kick panel, not working....bought a broken tach? . Got some long wire popped the hood to hook one end on the negative side of coil (...what’s this? the connecter is loose?.... Pushed it all the way down), started her up, tach works . So I tried the other connections agian hoping this might have been the problem, i turned it on and it didn't work, but when I touched the green wire from tach with the tach input the tach jumped around then stopped back at 0, not working. Anyway I hooked it back up to the neg on the coil and it works good, but it kind of has me worried, if there’s no tach signal coming from comp, maybe it's not getting one? Could this be related to my Code 212 crisis of earlier this month?https://www.ford-trucks.com/forums/s...75#post1582875HELP?

 

The fuse was fine but I replaced it anyway....any ideas out there?