2003 Yukon XL SLT - New battery and alternator. Having issues with volt gauge jumping around.

I have a 2003 Yukon XL SLT. Replaced the alternator in March 2024 and the battery last night. The voltage meter has always read 14.5 except when the alternator needed to be replaced. Now it goes from 11 to 14.5. Lights dim and fan slows when I slow down. Anyone else with similar experiences?

@cj 1990 Moved you here from 2021+section.
Welcome from Miami&NYC!

cj 1990 said:

I have a 2003 Yukon XL SLT. Replaced the alternator in March 2024 and the battery last night. The voltage meter has always read 14.5 except when the alternator needed to be replaced. Now it goes from 11 to 14.5. Lights dim and fan slows when I slow down. Anyone else with similar experiences?

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You have a corroded/loose negative battery wire OR another bad alternator OR something pulling a really heavy load on the alternator (Short to ground). Id check the battery cable first. Both ends of it.

Welcome from Colorado!

cj 1990 said:

I have a 2003 Yukon XL SLT. Replaced the alternator in March 2024 and the battery last night. The voltage meter has always read 14.5 except when the alternator needed to be replaced. Now it goes from 11 to 14.5. Lights dim and fan slows when I slow down. Anyone else with similar experiences?

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I have the same issue as well. I never noticed this before my hundred thousand miles but now noticed this after my current 115K miles. AutoZone Duralast gold battery and alternator. I heard that it will fluctuate between 11 and 15 as long as it stays between those lines you’re not hurting your vehicle and you should be OK. At times it will tip down to 11 and go back up to 14. I haven’t noticed anything with my engine, shaking vigorously or performance upon acceleration changing. I would think this would only occur when you have a sound system or something else hooked up for an aftermarket. As far as your last sentence goes, I have not had that issue.

Interesting Update; So after a couple months of this issue, I finally went to AutoZone and they upgraded me to the next higher up product with the alternator and going from the Duralast gold battery (had a bulge on the sides) to the Duralast platinum battery. I am now no longer experiencing this fluctuating needle/gauge.

Joe-ty said:

I have the same issue as well. I never noticed this before my hundred thousand miles but now noticed this after my current 115K miles. AutoZone Duralast gold battery and alternator. I heard that it will fluctuate between 11 and 15 as long as it stays between those lines you’re not hurting your vehicle and you should be OK. At times it will tip down to 11 and go back up to 14. I haven’t noticed anything with my engine, shaking vigorously or performance upon acceleration changing. I would think this would only occur when you have a sound system or something else hooked up for an aftermarket. As far as your last sentence goes, I have not had that issue.

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Wrong section for your year....but 2005+ rigs have RVC which is computer management of alternator output.