Hi there!
I have a 98 305 fi formula with the vats system and I've been having trouble with my ignition(not the important problem atm but if you have any ideas please feel free) when its cool outside my bird wont turn it's as if the ignition isn't sending any signal to the starter, lights cut on and everything and fans cut off when I try to crank the engine but that's all. And with my 65 hour work schedule i decided it would be more time efficient to bypass everything and hook a push button(currently residing in my cigarette lighter housing) and wire it from my alternator and the other side to the side post of my starter. And it does the same thing that my ignition has. I've checked continuity at every location I can think of, and that all is in order, but I have noticed the bottom of the push button gets damn hot as if the circuit has quite a high resistance.

my current theories are
A- I need to bump from a 16 gauge wire to a 14
B-The vats is killing everything with how many times I've disconnected my battery in the last week

 

You have to wire to the solenoid terminal of the starter.

It sounds like perhaps you should seek the assistance of an auto electric specialist. Push buttons run with large gauge wires off the alternator with no fusing.... You are asking to burn your car to the ground and it's fairly clear you have no business under the hood with wiring tools. This smacks loudly of zero electrical understanding and I kindly suggest finding some skilled help before something tragic goes down.

GD

 

I do have a fusible link and it's connected to the side post of the solenoid, the same side post you'd use to test a solenoid by running energy directly to the starter solenoid.

 

Then I would guess you have an issue either with the starter itself or with the battery terminals or cables. Side terminals are notorious for poor contact. Clean and inspect everything. Metal contracts when cold which may be causing no connection only when cold.

GD

 

The starter is actually brand new, until running into the problem with the push start I was convinced either my ignition was going as it has some play or the key reader was going.

 

What brand is the starter? Many of the parts store brands are absolute junk.

GD

 

I got it from advanced but it'll jump off a separate battery connected to the side post, I'm honestly thinking with the heat coming off the back of the push start that the 16 gauge wire is too small for the length of the circuit

 

I just tried to start it again with both the key and the button after making sure the keys resistor was clean and i did notice two significant differences between both methods. When pressing the button the interior lights dimmed and I noticed an electrical humming when the button was depressed, which also didn't happen when I tried to crank with the key

 

With the push button, the VATS cannot be in play. It would seem you probably have a cable/terminal issue.

GD

 

I rewired the whole circuit I got the car cranking but now its not starting at all anymore, I only had time to check the fuses yesterday so now I'm going to go through testing everything I can think of starting with my injectors, thanks for the help GD.

 

Depending on how you have it "wired", the key will still need to be in the "run" position while cranking to power everything up.

I highly recommend putting things back then finding/fixing the issue before there is a real problem.

 

Update i figured that the resistance reader went bad in my ignition so i bypassed it with inline resistors as I had some laying around and now my security light is off, and the car cranks with the key and push start everytime but its still acting as if its not getting fuel
and wont start