ke7omc

Hello,
I am having a problem with my tach. I have a 1993 Mustang 2.3L auto. About a year and a half ago my tach was reading half of its real value so I replaced the ICM and it worked flawlessly for a year. Then we did a transmission swap on it and it hasn't worked ever since. It just reads 0 all the time the needle never moves. I replaced the ICM again with a known good one from a spare car that I have and that didn't work so I thought it might be the actual tach so I replaced the gauge cluster with my spare one that is known to be good and still nothing. Does anybody have any suggestions on what to do because it is really confusing to me.
Thanks in advance!

ke7omc

I guess I should add that the last time I used the replacement cluster in the spare car was about a month ago. I know that sometimes the solder joints crack on these and we did have some unusual cold spells here in northern utah. Do you think it could be something other than the joints though? My car is at my parents place for the time being and my dad is trying to fix it for me to bring back to college so it will be he that is diagnosing the problems.

ke7omc

Ok despite a few weeks of trying to figure this out it finally was solved right after I got desparate enough to post. So if anybody stumbles on this in the future we found out that the rear coil pack was not hooked up for some reason. (One of the prongs of the connectors was broken and it might have slipped off or something.) The important thing is that we hooked it back up and the tach works. The tach receives its signal from that coil pack. So because it receives it from the secondary coil pack the car can still run just fine but not receive a tach signal. Solved. Hope that helps if anybody has the same blunder.