NEED HELP Intermittent Low Alternator Charge (guage&voltmeter), Intermittant (Just Clicks) Start issue

BLArtka

New Member
2002 GMC Envoy SLE 4x4

Bought the SUV a few months ago. A few weeks later I packed the car and went to leave for a road trip and starter just clicked and then nothing; then clicked again when trying to start. Needles to say the starter was not engaging so i had to jump across the contacts with a screwdriver and it started right up. Didn't act up again for a week or so then was fine. I noticed the volt gauge had started to fluctuate within the "middle mark" between the 9 and 14 and read anywhere from 11.6 to 13.5 when checking with a voltmeter. I checked with a voltmeter at the battery after the RED Battery light came on during my lunch break the one day and never returned after the next re-start. I had the battery checked, they said it was good. I thought Oh its the alternator.... It had a new alternator on it when i bought it and I know even new parts can go bad pretty quick so i had to get a used alternator. I took the used alternator and had it bench tested before installing it, It tested good. I noticed the connections on the starter looked corroded, I went to undo the nut and the whole plastic side cracked off the starter next to the terminal stud. Got a new Starter ($200) and it was fine and voltage was at 14 on the gauge for the ride home from where i work on it. Next day voltage was back down. maybe about a week later it started the Click...Click when trying to start it. I replaced the Ignition switch and the starter relay in the fuse box. No Luck. Sometimes it starts sometimes it doesn't start unless i pop the hood and jump the starter across the terminals with a screwdriver. Then it starts up after that. The security light also comes on every now n then (rarely)and just stays on till next startup. I did notice the other day that with the key out i could touch the lock cylinder and the gauges would come on (I was a tooth off when i installed and just fixed it today so it works as it should now.) I also noticed that if i am quick and heavy on the gas pedal the Speedometer will Jump around a bit but then is fine, all other gauges operate fine (other than the Volt gauge which is actually correct as it varies voltage measured at the battery) I noticed the Onstar light on the mirror is sometimes red and sometimes green. I don't really know where to go from here. I read a bunch of separate postings where some of the posting applies but not the whole thing. Any help is appreciated. I really don't have more money to keep throwing at it. Thank You
 

gmcman

Well-Known Member
You can try to wiggle the signal wire going into the alternator and see if it loads up. Mine did that once and with the high beams, rear defrost seat heat I could tell when the alternator loaded up.
 
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BLArtka

New Member
You can try to wiggle the signal wire going into the alternator and see if it loads up. Mine did that once and with the high beams, rear defrost seat heat I could tell when the alternator loaded up.
I tried that before but would only make a difference in voltage when the battery charger was connected
 

Mooseman

Moderator
Check all your ground connections, especially those on the engine block.

Other than that, what about a power drain? It seems to do it after sitting overnight.

What is your voltage while it's running? Still fluctuating?

Ultimately, you do get it going by shorting the terminals on the starter. Check out this video by @MAY03LT that should help pinpoint the issue.


If you're not getting that signal from the PCM, then there is something that is making the PCM not happy to want to start the truck.
 
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BLArtka

New Member
I'll test that stuff soon, but the car can sit all weekend and fire right up, I can drive to the store or wrk and when leaving it can either start or not, or if i stopped somewhere else afterwards it could start or not start, today it started today to go to work, it started when leaving work after sitting all day, it started when leaving the store on my way home, it didnt start after the second stop at the other store. Two days this week it wouldnt start when leaving for work, the other day it didnt start 5 times in a row. When it doesnt start i have to jump the terminals on the starter with a screwdriver then the key fires right up. But ill do the other testing suggestions soon and see what happens, Thanks
 

AtlWrk

Well-Known Member
One member had the starter solenoid wire itself break deep inside the wire harness (purple wire IIRC). After tracing/replacing literally every other part of the starting system it was the only thing left. If yours is breaking/broken then that could explain the intermittent start since you've already replaced most of the other culprits.

Erratic speedometer readings are either a bad ground on the engine block under the PCM (there's a TSB about it--clean and tighten them up), or the stepper motor in the cluster is failing.

The security light and on-star lights may also point to databus failure which could make the PCM not want to engage the starter.
 
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BLArtka

New Member
SOLVED>>>>>>>>

If you are experiencing these problems or similar replace your battery cables. I replaced both cables although the positive didn't make a difference but i replaced it anyway but all problems were gone after i replaced the negative cable, the cables seemed to measure voltage fine but neg was corroded and brittle inside and around where it was grounded to the strut tower. I tried taking that bolt out of the strut tower and it snapped off (be prepared for that) my dad had to make a new ground cable to bolt attach/ground it elsewhere to the strut tower and to to bolt it to the cable where originally attached. Also be prepared for the bolt where the neg cable attaches to the engine block to snap off, in which case i grounded it to one of the air conditioning bracket bolts. It has been about a month and i have not had any of the charging, starting, or weird gauge issues since. I bought both OEM ACDelco cables off of rock auto shipped for about 83 dollars.
 

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