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2000 gmc yukon charging failure

Recently replaced starter, alternator, and battery, but now it hasn’t been charging the battery at all. Took to mechanics, told me problem lies in instrument cluster. Was wondering if anybody ever had same problem

Can you tell me how you came to the conclusion that the battery isn’t being charged?

If you took it to a mechanic, I presume that it does start.

First, check that the battery cables are not terribly corroded.

The first thing to test while it’s running is the voltage at the lug on the back of the alternator.
It should read between 13.5- 14.5 volts.

If you get good voltage there, the next step would be to shut the engine off and check that same lug. It should read around 12-12.5 volts. If you get no voltage, the fusible link is burnt out.

Yosemite

the dash gauge could be bad- from what you say, this is what your mechanic is suggesting. Verify with a voltage meter as others have suggested.

Just that it’ll visbly drop on my car’s volt meter, and that I have to take it out and put on a charger every 2 days, or it’ll drain until its dead. Also noticed when I put meter leads to it it stayed at 12.4, with a.c and lights on it drops to 10.2

12 volts = 50% charged battery.

Tester

It starts, cleaned my terminals with abrasive cloth and no wiring is bad, all my fuses and relays are good too.
Volt meter reads 12.4 when it runs, 10.2 with lights and a.c. on. One thing I forgot to mention, is my check gauges lights came on, but my gauges dont seem to have changed at all

That’s too low. If accurate there’s some kind of problem going on there. The next step is to determine the charging current in those conditions. If the current is ok but the voltage is low, either the alternator or its controlling electronics is faulty or the pulley isn’t spinning as fast as it should. Before going further ask you shop to read the diagnostic codes in computer memory and post them here.

Okay, so I had taken my Yukon to get codes read and nothing came up. Check gauges light is still on but now, my oil level gauge is completely zeroed out. Its the only gauge on thw dash that’s not working now