Intermittent starting problem

[xops]

I have a 2002 L200 automatic transmission with just over 70,000 miles. Went on a trip from Salt Lake City to Phoenix last weekend. Halfway there I stop for gas and when I go to start up again, engine doesn't turn over. No clicking sound, just nothing. Had headlights and dash lights. Asked for a jump even though I didn't think it was the battery. It wasn't. Jump didn't do anything to help.

Stumped for awhile, I thought either the starter has a bad spot or the safety switch isn't engaged even though the gear shift was in Park. So I jiggled gear shift lever while my son rocked the car a bit. Tried again and it starts perfectly, everything back to normal. Made it to Phoenix without further incident thinking I dodged a bullet.

Returned home on Monday and parked in my driveway to unload my stuff. Went to start up again to take my son home and same thing happens again. Won't start, no noise, no clicking, with dash lights. As my son finished pushing it to make way for my other car in the garage, I tell him to try starting it again. Sure enough, just like before it starts up fine like nothing happened.

So today I take into Saturn dealership to have it checked out. Of course, it doesn't fail for them so they don't recommend any changes. Had it failed, their test is to bang on the starter to see if it kicks in.

Having read a similar thread here
/forums/showthread.php?t=140642,
I am wondering if the problem could be the Neutral Safety Switch that is failing or out of adjustment. Or is this a sign that possibly the starter solenoid is malfunctioning. The two times that it failed, the car had been driven hundreds of miles in high temperatures with A/C running.

In thinking back, I've noticed a couple of odd sounding starts over the past six months as if starter motor hesitated for a brief moment.

Any suggestions on what might be causing the problem?

[bigapl]

I would lean towards starter or ignition switch, I have seen both fail but tough to troubleshoot unless it occurs. The ignition switch get power from battery then runs through the neutral switch to the starter I usually check for power there at the yellow and purple heavy wires while in crank position and that tells me if the switch is good and park switch is good if both have power. If you have power there then probably starter issue.

[fdryer]

1-What conditions are the battery cables in? Early starting troubles were caused by faulty ACDelco batteries cracking its RED positive side terminal, leaking acid into the battery cable to eat away the copper wires unbeknownst to car owners. Are your battery cables showing signs of corrosion? Lack of battery cable maintenance can lead to corrosion, corrosion can lead to poor current transfer for the starter, a possible erratic no-start condition. Starters use welding current and require the best battery cables in good condition. Nothing else in the electrical system requires large gauge wires like the starter does. Be sure the battery cables are in good condition and free of any corrosion before continuing with more serious troubleshooting.

2-You can eliminate the Park/Neutral safety switch the next time the car won't start by shifting to Neutral when it won't start in Park; either position without a start most likely means its not the switch as you can jiggle the shift lever in each position a little to help the switch's 'sweet' spot pass the START signal to the starter solenoid. With no start in either position you're left with the starter being suspect.

3-As suggested, if you checked battery and cable connections, you're left with crawling under the car to check and measure for the presence of the 12v/START signal to the starter solenoid small terminal that has the purple wire. Remove the wire to test it "live"; use either a 12v bulb lamp test or voltmeter to measure this wire for the START signal when someone turns the ignition key to the START position. If the bulb lights up/12v is present (in either Park or Neutral position), you probably have a starter problem.

[xops]

Battery connection and cables look clean with absolutely no sign of any corrosion so I think I can rule that out as the cause.

Next time it happens, I will try moving the gear shift to neutral to see if it will start. If I understand you both, if it still fails at that point, that pretty much eliminates the Neutral Safety Switch as the failure point.

In both instances when it failed, it was like an open circuit with no power getting to the starter. Would the fact that this happened after long drives in the car have any bearing? If the starter has a dead spot, would it be symptomatic in this way?

Thanks for your replies.

[fdryer]

By being aware of moving the shift lever from Park to Neutral, your chances of a faulty neutral safety start switch becomes less and more so if you try any other position (keep your foot on the brakes just in case it turns out to be a loose nss switch that allows starting in Drive or Reverse) resulting in no start. All the nss switch does is ensure (when adjusted at the assembly line) that the starter will only crank in Park/Neutral for automatics or when the clutch pedal is pressed to the floor to close the nss switch. Any start while moving the shifter then indicates a misadjusted or faulty switch. Eliminating this switch from fault leaves the starter and the battery cable wiring to the starter. 70,000 miles isn't very much on the original(?) starter so it can be loose connections on the starter, loose ground, or failing starter.

Long drives may imply a heated starter but it still cools off with the rest of the engine. This can imply a faulty component somewhere, something as simple as a loose connection or a truly failing part that only fails from heat. Similar to many crank position sensors that have failed when the engine is warmed up and immediately kills the entire EFI system only to work again after a cool down and repeat again. This doesn't occur to many Saturn starters though.

[xops]

Originally Posted by fdryer

70,000 miles isn't very much on the original(?) starter so it can be loose connections on the starter, loose ground, or failing starter.

Your assumption is correct. It is the original starter and I've owned and maintained the car throughout it 70k life. Thanks for the clarification.

Though one might expect the mechanic at the Saturn dealership should have checked the obvious causes such as loose connections when I took it in for a diagnostic, I will still get my son to get under the car and double check.

Then it's just wait till it fails again.