2001 S-10 Pickup 4.3 AutoMatic Trans. 140,000 Miles. Problem: Intermittent No Crank No Start

This is my first time posting in several years. So, I’m not even sure I’m in the correct Form. But here goes. This problem has been going on for about 3 months. I drive the vehicle almost every day. I’m retired, so I have a lot of time to figure this thing out. Hopefully I can fix it myself. No pattern seems to exist. I have "kind of"eliminated some causes. They are: Neutral Switch, Starter, Starter Relay. Neutral Switch: It doesn’t seem to make any difference, if I move the shifter around while the key is in the crank position. When it cranks its always in park or neutral. Starter: I ran a jumper wire to the starter, it cranked over. . Starter Relay: I checked the Relay, it will click when the ignition switch is in the crank position. I talked myself into believing it was in the ignition I replaced the Switch Interruptor and it worked fine for a couple of days, about 10 or 15 cranks and starts with no problems. When the problem occurs, I might turn the ignition once, no start, second turn start, or it might not start in 15 attempts. 20 minutes later try again, starts on first turn. I’m limited in my knowledge of electrical systems. I know how to use a voltmeter, but that’s about it. I’m 74 years old, do most of my own car repairs, change oil, grease job, brake jobs, change out parts etc. But this problem has me stumped. Any comments and suggestions would be appreciated Thanks: airdropbill

There’s usually two electrical terminals on the starter motor. A big one, and a little one. Use your voltmeter to measure the voltage on both those terminals during attempted cranking. Measure between the terminal on the starter motor and the starter motor case. Let us know what they measure.

Thanks, I’ll do that the next time the problem shows up. I never know when its going to do this, just no pattern, I’m have always suspected a bad ground somewhere, I’m not going to replace any more parts just on assumptions. A fellow could go broke doing that on a S-10. I’ve owned the vehicle for 11 years. Never had a problem it I couldn’t fix, until now, Thanks: airdropbill

Good plan. With newer cars especially, you can run out of money before running out of ideas of things to replace.

Until now, it has been a very reliable vehicle, I purchased it 11 years ago, it had 40,000 miles on it. Minor maintenance problems was about it. In the last 18 months, I’ve replaced the radiator and fuel pump and now this problem. When I get this fixed, I think I’ll let it go. airdropbill

A vehicle needing a new radiator and fuel pump isn’t anything unusual at this age and mileage. It’s true though that after 100K you’ll have to plan for more maintenance and repairs than with a newer car. This no-crank situation is pretty common one we have reported here too. It should prove pretty easy to diagnose and I don’t think you are looking at much money to fix it, at most you’ll have to replace the starter motor maybe. And if you feel lucky, even if the starter motor is the problem, you might be able to get it fixed instead of replacing it. On my early 90’s Corolla the crank-up design a weak point, and I’ve had to deal with it a number of times. But I’ve always managed to fix it when the starter motor is the culprit to just fix the starter motor itself. Last time it cost me the whole of $10 for new solenoid contacts.

You might check the junction cable terminal. There should be 2 leads from the battery positive terminal.
One goes to the starter motor and the other to a junction terminal located near the battery.

If the junction terminals develop any scale or corrosion everything on the vehicle may go dead. The only thing that will receive power is the starter motor windings but the starter will not work because the starter solenoid is inoperative due to lack of power through the junction terminal.

If the junction terminal is the problem there should also be a lack of lighting, wipers, etc.

Thanks ok4450: I checked and cleaned all the grounding points from the battery. All lights are bright and working. Battery voltage to the starter is good. What I haven’t checked yet, is the drop voltage to the starter when it won’t crank. What puzzles me is it’s a intermittent problem, which in my limited electrical knowledge, I’m believing it’s a ground problem somewhere else. But, the next check will be a drop voltage check when it does it again. That might be the next time I try to crank. Or, the 20th time I try to crank, which could be sometime next week. I never know. airdropbill

Intermittent “fails to crank” is very common. I can’t speak to your specific vehicle, but on my Corolla the starter motor solenoid design has a gadget shaped sort of like an intake valve, a copper mushroom attached to a long stem, spring loaded. When the solenoid is activated in “start”, the magnetization is strong enough it pulls that stem down so the underside of the mushroom presses hard against two copper contact plates. That powers up the starter motor windings. The other end, the stem, simultaneously pushes the starter gear out to engage the flywheel.

So what does this have to do w/it being intermittent? You remember back in junior high when you put a magnet under a piece of paper containing iron filings? How the pattern would sort of form circular shaped twirls? That same thing happens when the solenoid is magnetized. And it produces a twisting force on the mushroom thing. So it rotates a little each time it is activated. If there are bad spots on the underside of the mushroom, burned spots, it’s like a roulette wheel. It will work sometimes, not others. Eventually all the good spots will get burned too, and it won’t work at all.

Ground points have nothing to do with the junction terminal though. That’s on the positive side of things and junction terminals can cause intermittent problems.

Things may work fine for months and then suddenly one day everything is dead when you go to start the vehicle.
There should be 2 leads from the battery + post and the smaller one should lead to the junction terminal.