Charging Problem - Fluctuating Voltage

[01YUKXL]

I saw a similar post on this but can't locate it...

My 2001 Yukon XL is having a charging system problem.

Two days ago I noticed the Voltage reading was fluctuating between 12.5V and 14.4V...as the battery died the the lower limit dropped down to the 9 to 10V region on the gauge.

Did some checks with the voltmeter to confirm what I was seeing...and replaced the battery and alternator. The problem is persisting both at lower and higher vehicle speeds and RPMs as the voltatge gauge fluctates and eventually looks like the system is not charging. Battery is getting drained.

It looks like the next step would be to replace / add additional power and ground wires between the battery/alternator/chasis.

Any other advice? Any info on computer checks?

 

[blueflamed03]

Doug, are you sure on the voltage and it is still indeed dropping, and not a faulty gauge?

 

[chip]

Yeah, that sounds weird. Turn the truck off diconnect the negative cable and see if there's a draw (with your DMM).

 

[01YUKXL]

Doug, are you sure on the voltage and it is still indeed dropping, and not a faulty gauge?

Tracy, I used a digital multi-meter while at work on the Yukon before I replaced the battery and alternator and it appeared to be showing the same results as the gauge. After I replaced the battery and alternator I had Autozone hook up and there diagnostic meter and that also showed the same general voltage levels as my gauge. After 20 minutes yesterday my radio started cutting out and the voltage had drained down to the 9 to 10 volt level so it definitely is loosing juice and not just a faulty gauge.

The battery light on the display gauge comes on for 4 or 5 seconds and then shuts of repeatedly but for some reason no OBD2 codes show up on the auto zone obd2 checker.

 

[blueflamed03]

wow...somethings really going on to have that kind of drain on the system !

I'd suggest a shop or dealer, not sure where to start. Sorry.

 

[Eagle]

sounds a problem with the charging wire.

Open the orange cover, the Alternator wire is crimped to the battery wire... Could be an issue there, corrosion in the wire, etc.