'97 GM 350" truck starter (pt# 12563829), almost exactly one year old, on my '73 350". Worked flawlessly with my old engine. Two weeks ago I got the rebuilt engine in & running. It's hopped up but nothing radical (see sig). 9.75 compression, mild cam, wrapped headers. Everything OK for first week, then I drove it to the "'Vettefest" where it was parked in the sun on a 90* day for 3 hours. Engine was still too hot to touch when I left. Starter just clicked. Jumped it with a screwdriver across the terminals, varoom, started strong. It did the same thing that afternoon at the Good Guys car show, after 3 hours parked in the hot sun. Park in the shade, no prob. Let it get cool, no prob. First start of the day, no prob. OK, heat soak on the connections, right?
Saturday I went thru and cleaned and put silicone dilectric grease on all battery, starter, ground, alternator, horn relay post, and other miscellaneous connections. OK all weekend running around the county parking, starting, stopping, city and backroads, in 85* sun: problem solved, right?
Today, 4 hours after I arrive at work, parked in the sun, 75-80* out, starter and engine nicely cool, it does it again. Click. Jump it with the screwdriver, varoom, fires up strong.
Of course it never does this when I'm anywhere where I could do any real investigating, only in public places where I have to act real suave and cool as I'm popping the hood and poking it with a screwdriver to get it to start....
I have not done a voltage drop test on the starter yet as I thought I had it fixed. Neutral safety switch seems to be working correctly. No other electrical problems. Starter works great, strong, no sign of struggling. Any body got any ideas to guide me? Now I don't think the heat has much to do with it after all, & I don't want to just arbitrarily start replacing parts.

Thanks,

John

 

You've problably already checked to ensure the wires are clean and tight?

 

Didn't do resistance tests, but wiring all looks in good condition, good attachment to OEM connectors, no frays or loose strands, connections tight.
For what it's worth, I've also been chasing down a coolant leak at the heater core. It had been dripping off the hose and splattering the underside of the car. Fixed the hose leak and today the heater core ruptured on the way to work. Soaked the passenger side foot well. !@#$%%^&*!!. Didn't overheat the engine, only lost about a gallon of coolant. However, there is no sign of coolant on the starter or connections or plastic split-loom the starter wires are in, no moisture or slime.
I guess tomorrow or Wednesday after work I'll try some voltage drop & battery tests.....
Ding dang it all! I wanna be dialing in my carb right now, not forking around chasing BS like coolant leaks and starter problems!!!!

 

High resistance in the circuit combined with heat.

Trace the resistance down and repair it or you can just barn job it quick and dirty with a Ford starter relay. At least you can turn the key and start every time.

-Mark.

 

Yeah, I got no problem with the Ford relay, already printed out the info for my file. But I want to fix the problem, not circumvent it. The Ford relay would just be an "extra." I just hope that my voltage drop tests later this week don't open a whole 'nother can of worms.....
In my effort to "always look on the bright side of life", I find now that since I have deleted the leaking heater assembly, my cooling system is now able to pressure up correctly and I'm running 10-15* cooler....

John

 

 

Well it looks like not too many people care, but for those who do...Tests indicated all wiring, connections and battery just fine. I got a bad starter. Found my receipt, it's only 6 months old. Poop. Oh well, that's probably the easiest thing to fix. Could be worse, I'm OK with that.

John

 

John, Is there a test that let you determine specifically that the starter was the problem, or was it through process of elimination? I'm experiencing similar symptoms (e.g. won't start after sitting in sun). Like you I have already replaced starter (and neutral safety switch, starter interrupt). It starts if the neutral safety switch is bypassed. Seems like the switch might be bad, but may be misleading.

Thanks, Jerry