1998 Chevrolet 3dr Silverado 5.7

I just replaced key cylinder and radio without code started my problems.I had to reset my computer so it would crank.Now i can drive it during the day but can't drive it at night.At night it cranks up for about 1 second and dies.Its driving me nuts.Went to Auto Zone and they checked it for codes but there was none.Any ideas would be appreciated.
Larry

 

If you're being serious, the only thing imaginable is an elaborate prank using a solar cell and relay that acts as a kill when there is no power to the cell.
When did the problem start? Was it out of your possession at all?

 

2 months ago.It used to have remote start till i took it out.It all started when i pl,ugged a radio i got out of another chevy truck.Replaced key switch because it would not turn,reset computer by turning it on and off 3 times and that got it cranking during the day.

 

Never been out of my posession and radio is unplugged because i hear you gotta have code.

 

Still won't start at night? Is it at a certain time of day or when it gets dark?

 

Also, did you have ANY issue with the remote start shop? Haggling? Installer that rubbed you the wrong way? Anything?

 

It was in the truck when i bought it.Truck ran just fine for a year till switch got hard to turn and i plugged new radio in.Havoc started right then.Its real cold out and in the middle of the day it would not start.Its my 2nd truck so i am just curious about what went wrong.No hurry just like things like this....lol

 

After months of truck sitting i have discovered that when its cold (60 or below)it will crank and die.It was 64 a few days ago and it cranked right up and i drove it all around.

 

I drove it around.Stopped twice and cranked back up.3rd time i parked it under carport in the shade and it would not crank.Pushed it out in the sun and 30 minutes later it fired right up