Starters are a known factor because what happens is the act like a heat sink near exhaust manifolds.The starter switch is way,way,far away from that.Might be the O.E.M. install of a starter on yours had a heat shield and during a swap someone dis-guarded it.Might want to look at one at a pick and pull to see if they have them.

 

Ok, now i ve installed a NEW starter and added a heat shield from summit racing, $9.95! problem SEEMS to have gone.
I m sure that starter heat shields were not factory fit, so it looks like it was the starter/solenoid all along.

 

The heat shield should prolong the starters life. Hope it is resolved. One other thing concerning the starter you said was checked good, was it bench tested or actually installed on a car?

 

The used starter i tried was off another car that never failed to start!

 

The reason I asked was bench test isn't the same as load test. Glad you got yours fixed.

 

ROUND TWO !
After installing a brand new starter and heat shield i m back to square one.
No cranking over after the truck has started from cold, then turned off.

This can only be the ignition switch. ?????

When the truck is started from cold, contacts in the switch pass the current through because of the low resistance. After one or two starts heat builds up ( high current generates the heat) gives a high resistance
and voila, no start.

Anyone agree, Steve?

 

The purpose of the solenoid is to engage the starter, and turn the motor. The switch just engages the solenoid. You say new starter, new solenoid also? You might otta check the connections, especially the large cable to the starter solenoid.

 

Yes BRAND NEW starter and solenoid as a unit, don t think anyone sells just the solenoid for this particular starter. When it does work it cranks over faster than the old one for the two seconds or so before it fires.
All the connections are spotlessly clean and tight.

 

Your thing about the switch is out in orbit to me, however as I posted earlier (now with key off) when it is hard to crank, use the screwdriver across the small terminal to the large terminal at the solenoid that will tell if it is (yea I know new) solenoid or switch. If hard to crank from the keyswitch, but not from the solenoid, that would indicate either switch or wireing from switch is the issue. Also, is this happening like "clockwork?" as in, i.e runs 20 minutes to store, shutoff, then problem?

 

Basic tests like you describe show the problem to be upstream of the starter and its probabably this dam ignition switch. Apparently lots of stuff runs through this thing. I hate working on computer controlled crap, prefer my old vette, its simple.
The problem occurs randemly, after 1 start/stop, 10 min drive or a few cycles/days.
Makes the truck unreliable and its my daily driver, wife wont drive it, she loves her subaru, yuk, but it IS reliable.