Any one else ever run across this? what to do to fix it? Thanks

Sounds like you've got the power wire tapped to the lighting circuit, instead of "IGN". Does the lamp (tach) come on when you turn the key??

No it does not come on when I turn key on,thanks for the quick responce!

anyone else? need all the input i can get, Thanks!

Look at the fuse box. It sounds like the power for the tach wire is plugged into the lamps connector. If it is, move it to the ign connector. It sounds like John said. You are getting power to the tach when the lamps connector is hot. You can follow the hot lead from the tach housing to see where it goes. It needs to be hot when the ignition switch is turned on.