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02 Monte Carlo SS 3.8, Intermittent No crank


tunabreath

Question

2002 Monte Carlo SS 3.8, no supercharger. 65k miles.

Having an intermittent no-crank condition. Sometimes the starter solenoid will click, sometimes it won't. The starter is a 2 week old reman from Advance Auto.


Here's what I have done -

-Cleaned all connections including battery terminals, grounds, leads to starter and starter housing to block.
-Tested all wires for voltage drop and high resistance, nothing abnormal found.
-Verified operation of starter cranking relay, swapped it with a known good one. Checked voltage at relay pins in junction block, all good.
-Tested all fuses and checked for loose fuses.

-ignition switch was replaced 4 months ago, took it apart and inspected contacts, all good no corrosion or arcing.
-jumped the battery terminal on solenoid to S terminal on solenoid. SOMETIMES it cranks, sometimes nothing, not even an arc.
-checked for voltage at S terminal while ignition in START, couldn't get reading even when starter cranks or doesn't crank. Too quick for meter to pick up?
-removed starter from vehicle, bench tested it. Can not get it to act up, works OK.
-battery maintains 10-11v while cranking.
-Engine is not seized.

2 odd things-

Once in a while when the starter does function on the vehicle you will get a few sparks falling from near starter area, too quick to see where from.

Once, when holding ignition to START and nothing was happening, a RED/BLK wire heated up and burnt insulation off. This wire comes from the ignition module and runs to PCM. The area where it burnt up was at connector C110 located under the engine cover. It is the "LOW REFERENCE" to PCM. Why would there be that much current flowing through what is essentially a ground wire and why has it not blown a fuse? On a hunch, I swapped in a different ignition module thinking something was internally shorted inside this one (replaced it due to a phantom misfire 2 weeks ago), but no change. Back to the new module.

I'm lost. Right now the starter is off the vehicle and I am letting it sit to see if I can get it to malfunction while bench testing.


Also, no Security light flashing. Just the normal pulse when key is ON position from BATTERY to SECURITY which is normal.

Any help is appreciated!
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Govtech4 has been on here much longer than you have so some respect would be appreciated. We don't like it when people cause problems on the site, disrespect like that can get you banned. Also i'm confident rob has much more diagnostic experience than you. I'm not saying anyones right or wrong.

He obviously has been on here longer than me. However, he started the name calling and immature, disrespectful verbiage. So if he wants respect from me or anyone else, he shouldn't have to stoop to name calling. Also, I have been around long enough to see these mysterious intermittent no crank MC's and Impalas fixed by replacing the BCM. Nobodies lengthy list of diag experience can change that. No disrespect to you intended. Thanks.

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You need to get over yourself. It's not healthy. You can live in denial all you want, but it's not gonna get this guys car fixed. We've replaced many BCM's for an intermittent no crank. Do yourself and the op a favor and do some research before running your internet mouth off without a clue.

I didn't make the mistake

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Might have got this thing figured out.

 

I was lucky enough to catch where the spark came from. I found another ground on the trans bell housing. It was a long stud and the nut seemed tight but it actually had a thread or 2 more to go.. It was pretty corroded but not terrible. I took the leads off, cleaned the leads and the mating surface. I started it three times, going to let it sit for a while and see what happens. Thanks to all.

 

 

 

In your original post you mentioned a wire got hot and started to burn insulation, and you commented that it essentially a ground wire. Having the loose ground on the bell housing can cause the electrical system to find the next good ground and use it. Problem is, the starter can draw a burst in excess of 200 amps. If ground is bad, that current has to return to the battery somehow. It is amazing how many times that an odd starting issue goes back to ground connections. There is a good chance for some hidden damage to occur due to some expensive parts. Wheel bearings do not like 200 amps going through them for example. The initial run of the Omni and Horizon model cars back in 77-78 had bad or missing ground straps from the body/chassis to the engine. Depending on how cold it got in the winter where the cars were being used, you may get 2 winters out of a set of front wheel bearings. Factory ground straps were those braided stainless with a slip on clip on each end, similar to the hood ground straps you see on some trucks.

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I have had the starter off the car now for 24 hours. I have probably engaged it several dozen times without an issue.

I have a subscription to Chilton's and have the starting circuit diagram. Everything checks out as it should.

 

This starter is going back on the car for one more round of testing. I have no idea what else to check.




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You need to get over yourself. It's not healthy. You can live in denial all you want, but it's not gonna get this guys car fixed. We've replaced many BCM's for an intermittent no crank. Do yourself and the op a favor and do some research before running your internet mouth off without a clue.

Relax

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