03 lb7 security issue?

[michaeljm]

High mile truck.. Recently had a fuel issue that seemed to be partial electrical... Truck shut off on me multiple times and lost fuel pressure ... Changed out the cp3 high pressure pump and it ran perfect for about 100 miles.
Since I bought the truck I have been having these issues
-Security light flashes nonstop but the security has been hard wired to the fuse box by a switch ( didnt drive it like this without an issue so im not sure if it worked good for it or not but it isn't right either way)
-was told its possibly something inside the drivers door panel
- shut off 10 miles after I played the damn thing
- lights didn't dim in the dash just cut off
-cranked over strong until I gave up
-secondary battery ground was a little loose don't think it would be loose enough to cause a issue
-yes I have good fuel pressure
Any help would be appreciated thanks

[michaeljm]

"Played" supposed to be plated it was down for 2 months needed it to plow the night I got it back is the night it broke down... Which luckily the storm didn't come through but need to fix ASAP as its my work truck