Ok, so I took my serpentine belt off my car the other day because I wanted to check to see if my waterpump, or another pulley was making a knock/tapping sound in my car. Well after I got the belt off, and started the car, I still had that sound So I put my belt back on, and fired up the car. To my surprise my tach has stopped working....Wtf?!!? Any ideas why it has stopped working? All I did was mess with my belt....and I'm not the greatest with cars but I thught the tach read the rpm's from the distributor, right? So I'm lost now....please help!!

 

It shouldn't have anything to do w/ the tach. Check the wiring going to the coil.

 

Quite a few tachs now take a signal off the newer style alternator. That doesn't explain why it still doesn't work after you reinstalled the belt. Are you using an older SI alternator or a newer CS alternator?

 

Honestly AlkyIROC, I have no clue what type the alternator is, my car is a 1992 305 L03 with a 700r4 if that helps at all. Also my tach worked and read rpm's fine until after I put the belt on, wish I had looked to see if it was working when the belt was off, but I was to into what I was doing.

 

So, just a quick update for this thread. I drove the car around for a few days with the tach not working. Then this morning, started the car....BAM, the tach is woring again. So far so good! Checked the connections, everything seems good, so not sure what was up with this problem...but happy that it has seemed to fix it self!