99 k2500 starting issues

[realityabq]

hi all

been lurking for a while now, first time posting hoping you awesome folks can help me out.

 

I've got a 99 suburban k2500 with the 454. got it for cheap recently when the last burb died out.

the big problem now is that it doesn't reliably start. this is an improvement on the no start that left me stranded a month ago, yet still no good.

this truck has spent its life in NM and Arizona. hot and dusty. most of the plastics are brittle at best. mainly dust stuck together with grease

 

beginning of problems:

 

left the lights on and the battery died.

no start on jump, no click, nothing at all.

replaced starter and battery, no luck

found bad battery wire going to starter, replaced all power wires in truck that I can get to. started up.

then started blowing the crank fuse (#8 in cab fuse box). replaced and is no longer blowing out

installed second battery and isolater, mainly to have a charged backup if needed

truck will start up perfect 50/50. other times it'll crank once then act as if the battery is dead. after the first crank, nothing at all, no click no buzz.

all other power is working great, battery and alternator test good and show correct voltages.

tried tracking the crank cable from the starter up, found some burned wired and fixed them but guess none were the crank wire. (I'm calling the smaller switched wire the "crank" wire, if there is a correct term please let me know)

still iffy on starting.

 

this brings us up to today

 

 

what I want to do now is replace the crank wire completely as I think it might be pinched or burned somewhere is the guts of the rig. But where the hell does this wire go???? I can track it up into a heat shield that goes over the exhaust from below, but can't get in enough up top to find it from there.

this is a thicker purple wire. my guess would be that it should go to either the underhood fuse box ign A or B fuse or in the cab??? I've found about 5 purple wires and don't want to pull out any more if I can help it.

 

 

any help is greatly appreciated.