WarriorBambino

Okay so I started a project car about a year or so ago and I've run into a few problems here and there which I have corrected but now for whatever odd reason my mustang won't crank just from turning the key. I have gotten the keys and computer flashed and programmed and it has a new battery and everything else checks out. I even installed a new fuel pump. Now when I hook up a wire I set up as a bypass the motor cranks up and runs but if I disconnect it after cranking it it slowly dies out and I think it is sending a reverse polarity signal which burned out my original fuel pump to begin with. I want to assume it may be the ignition starter switch but I'm not for sure until I change it out. Any suggestions from anyone who has conducted an engine swap like this before?

LilRoush

You need to tell us more. A V6 swap has a LOT of stuff people tend to skip that can cause issues. What all got swapped over so far?

WarriorBambino

I have swapped the motor, transmission, engine harness, dash harness, and the ecu. The ecu has been reset and flashed for the keys so the anti-theft is no longer activated/engaged and the electrical components are all of the motors original vehicle it was pulled out of. The original motor was a V6 with automatic transmission and I swapped it out for a 4.6L V8 with a 5 speed transmission.

LilRoush

I agree it's something electrical in the ignition. Did the V6 in it prior run ok or was is dead to start with?

WarriorBambino

The V6 cranked up just fine it was just suffering from some severe oil leaks but within the week we swapped over to the V8. Do you believe that it may indeed be the ignition starter switch that may be causing ignition problems with this motor?