I have a 90 Foxbody and in order for the turn signals to work or heat to blow I have to start it then turn the key back a tad until they come on, and when you go down the road sometimes before I can use the turn signas I have to turn it back a tad again. It has a brand new key and cylinder. What would cause this?

 

It sounds like the contacts in your ignition switch are starting to wear out causing your ignition and acc voltage to drop out. The problem is in your ignition switch.