98 Yukon Battery/electrical problem

[YukeDuke]

I replaced my alternator after it tested bad. Then replaced my battery. At first the gauge showed a good charge. Then after driving with either the headlights, air conditioning, or both, the gauge shows a drain. I have to use the battery tender every night. I replaced the alternator under warranty a second time and the shop says it charges fine. Any suggestions?

 

[Gzes]

Bad battery

 

[_Dylan_]

Are the battery connections good?

 

[YukeDuke]

All connections look good. One terminal recently replaced. No change before to after.

 

[SunlitComet]

are your engine to frame ground on right side of engine intact and corrosion free?

 

[Donnie Yukonie]

is there a relay for the alty? if so maybe a sticky relay?

 

[YukeDuke]

Ground strap and relay

Not sure about the ground strap. Will check it out tomorrow. Sometimes I see the gauge move towards 14 as if it is charging but it is still on discharge side. Will have to look into relay as well. Thanks for the leads!

 

[retorq]

Forget the gauge, they are notoriously bad or read low. What does the battery say with a multimeter across it when the engine it running??

 

[SunlitComet]

no relay make sure with key on you get batt volts at that 1 wire connector on alt if voltage still vary as measured at alt post, usually a sign of internal damage.