JpEg625

Hey gear heads!!

i've got a 1985 mustang gt, 5.0 five speed car w/carb. I purchased a dash mount 5" tach. i've had major headaches getting this thing to function...

i've heard rumors that some tachs might not work with the mustangs ignition system??

Can anyone shine some light on how i can add an additional tach to my dash, wire it properly so that it will function..

right now it will function after you get to about 2500 rpm, but the shift light goes nuts most of the time.

sorry if this sounds like a stupid ?, but i'm done busting my chops on it, can you help?

thanks!

nitrous_bob

where did you hook it to ? and do you have a MSD box ?

tinman

Sounds like you need to check ground wire, black wire most of the time.
Get it to a good ground.....
If it's an 'Autometer' or 'Autogage' brand there has to be a fuse in the power wire 1.5 amp if I remember right.
If you have either of these tachs PM and I can get you complete instructions.......

JpEg625

ran ground to the battery, perhaps i need to view the connection again. no msd, factory ignition, but i replaced the ignition box last year. i ran tach signal from that output on the box. power wire is on the coil??

JpEg625

ground ran to battery, i will check its connection.. power wire running off coil, and green tach signal is ran out of the ignition box, have also tried the coil. it is a cheaper tach, not an autometer, does have an inline fuse.