I've got an 89 formula with the 305 TBI and 700r4. Last week I got a no crank no start condition. I replaced the starter and everything worked perfectly for 4 days. Then the same thing happened. Everything powers on, temp gauge pegs when I turn the ignition. The security light turns on for a couple seconds, then goes out. All i get is a single click from the starter relay when i turn the key.I ohm matched my key to bypass the VATS and changed the relay. The only thing that seems to work is if I disconnect the battery for a while and hook it back up. Then its starts a few times and goes back to doing the same thing. I'm at a loss and very confused on what it could be.

 

Has nothing to do with VATS, this is just basic starter circuit. Do you own a multimeter? If you do start measuring voltages at all points and report back, if not buy or borrow one. #1 on the list is clean both ends of BOTH battery cables and make sure all connections are tight.

 

If you get a click out of the starter, that means start request has been honored and is being processed so you can rule out anything computer related. You say you get bulb check in the start position, does it stay after the click or do you lose it? If it stays that likely means your engine ground is bad or the battery is suspect. If bulb check drops out with the click and comes back, its a weak battery or bad positive cable. One way or the other it's a voltage problem, grab a helper and a Volt/Ohm meter should be able to make quick work of it.

 

I've deduced it down to the ignition switch at the base of the column. I have it loose except for the cable running out of the back of it. I can't for the life of me figure out how to disconnect it without damaging anything. The correct replacement part for mine is a standard ignition US131 for context. Auto with a tilt column

 

I figured it out. Going to pick a new one up tomorrow and install it in the next day or 2