hello i bought a 2000 c5 im having trouble with it charging new battery new alt will show a charge then it will just stop i thought it might be a lose wire but it's happening when i shut the car off i can start the car 3 - 4 times and it will go back to charging kind of or miss
any ideas ignition switch ? maybe ? have checked all the wires seem to be good and tight

did check volt at battery 12.48 not running running under 12 at battery but back of alt showing 15. 6

2000 c5 35000 miles

thanks for any help

 

Occasionally you'll get a brand new battery which won't hold a charge. I recently had a red top tested by the local battery shop to rule out any issues with that, and it came back strong. I'm still checking, but it's looking like a PO hard wired in some audio component which is always on. Also, check the date on the battery. Where I got mine from (Autozone), the guy there made sure mine was in date.

Run a voltmeter on the batt while it's running - do you see the voltage increase with higher revs (to a certain point of course). Check any grounds on that circuit as well.

 

i ran volt meter it was running shows 11.54 volts but the back of alt shows 15.volts charge is not making it to the battery all the time but it does some time

 

Moved to C5 Tech.

 

If you see 11.54 volts at the battery with the car running but 15 volts AT the alternator you need to get underneath the car and check the alternator and battery cables at the starter solenoid…you may have a loose connection there or corrosion !!

 

i did check the wiring at the starter looks good and its tight the strange thing is it will charge at times but if i cut the car off and start again it will not be charging have to shut it off 3 or 4 times and then it will be charging again im starting to think ignition switch

 

Has to be the alternator or cable from alternator to starter solenoid, many C5 owners have opted to run a cable directly from alternator to battery.

 

That it “looks good” is not good enough !!…you have to physically remove the cables and clean them until they are shiny and then reinstall…ignition switch doesn’t have anything to do with the charging circuit…with your DVOM put either lead on the alternator case and the other lead on battery negative…set your DVOM on a 1 or 2 volt scale…the voltage drop should be low…way less than 500 mv’s !!

 

The wire from the alternator stud runs to the solenoid where there is a fusible link. Then, the battery cable that runs to the solenoid completes the alternator to battery charging circuit. That is it, nothing special and nothing that controls charging is in this circuit.

If the voltages are not the same between the stud on the alternator and the battery then one of those wires or connections has an issue, period.

Since it will start, the battery cable is likely fine. Either the solenoid connection is dirty, the fusible link is damaged or the wire itself is damaged.

 

well i found the issue its inside the starter solenoid this may sound strange but i poked it with a stick to see if wires were tight yes and it broke off right inside the solenoid crazy so now to the hard part changing the starter

crazy part the car would start with no issue whatsoever never showed sign of bad starter or solenoid


thanks

 

Good, that's the bad connection at the solenoid. The terminal gets hot from the loose connection and overheats the insulator which makes it more brittle and it breaks off.

 

yes looked outside but the inside was fried