Tach Problems

Well I jsut installed a small tach in my S-10 ... (Posted in another thread) and now I am having probelsm with it ....

I am trying to determine if it is a faulty tach or if it is something wierd with my truck??

I will not work after a cold start and I mean like sitting over night ... if I let it sit for say 3 or 4 hours then it works fine .....

After a cold start it will not work until I drive like 5 or six miles then all of a sudden it starts workiing ... It is not real cold here and all my connections are tiight ... I have the tach wire hooked up to the white wire between the dist. and the coil .... thiis is the negative side right ?? (The correct side of the coil)

After it starts working it is fine and never stops until it sits for awhile ...


Thanks ,
Branden

Anyone have any ideas ?? Think I need to replace the ignition module/coil ??

It should work anyway shouldn't it .. i mean there has be voltage flowing through the white wire or my truck would run like crap right ??

I would probably say bad tach... To be sure, simply check the connection to the coil... (Use solder). More than likely it's the tach itself though.