1992 GMC 1/2 ton starter problem.

First guess would be the starter solenoid, but it's usually cheaper to buy the whole starter/solenoid unit. Of course it wouldn't hurt to have the battery load tested before you go through the trouble of taking out the starter.

Had the battery load tested and alternator output checked. I'm trying to jiffy rig some improvement in the heat shield - perhaps adding a wrap or two of foil. I'm pretty sure the problem's origin is heat from the exhaust.

If you're going to try to wrap it, you might try an aluminum can with some type of insulation like ceramic glass inside. I have a 7.4l in the motorhome and it's gone through two starter solenoids. It might be heat, I don't know. I do know that the last time I priced the starter solenoid, it was $18 at Pep Boys, but a remanufactured starter/solenoid setup with lifetime warranty was $39.95

If you have a remote starter you can connect the starter straight to the battery and test it while the engine was hot. The only other thing would be the neutral safety switch might be failing. Some vehicles can bypass that by putting it in Neutral and trying to start

Aluminum can!! Great idea. Also, since I'll have the starter out anyway - necessary to replace solenoid - a warrantied starter/solenoid unit at that price makes sense. Do you have any idea if a bench test of the old unit would indicate which component is failing? BTW, a couple years ago I "straight wired" a starter circuit, using a push button activator. I was having difficulties then with my ignition key cylinder, since replaced,

A bench test would tell you if the solenoid is bad. I'm not sure where the neutral safety switch is, probably on the trans. With the 7.4 starter, the positive solenoid wire is right up against the block so it was impossible to remove it until I had all the starter bolts out. Problem was trying to hold up a 30# starter with one hand while trying to undo a nut on the solenoid. I just put my floor jack underneath the starter and after unbolting it I set it in the jack cradle while I undid the nut.

You have high resitance somewhere in the circuit OR the neutral switch is not working. Check and claen all battery connections, block grounds, and solenoid terminals. Adding a heat shield doesn't really fix the problem and it will only get worse with time.

ss195, I'm inclined to agree re; a circuit resistance. A year or so back I had a dash mounted push button starter circuit installed, bypassing the neutral switch. I think, however, the push button circuit was not wired directly to the solenoid/starter unit. After having replaced the solenoid a couple weeks ago, yesterday the issue reappeared. I guess I'll get under the old boy some time in the next few days, try determine how the push button circuit is now connected and then wire that circuit directly to the solenoid/starter unit - if don't stumble across a good deal on another pickup beforehand! Thanks for feedback everyone. Any others will also be appreciated.