Loss of power
When driving at night my Yukon looses power and voltage drops and dash light dim. This only happens when the headlight are on. New alt this past spring belts are not sliping. Not sure why only at night.
First double check your wiring, you may be loosing a ground pathway or a power feed as the demand increases, then retest your alternator for proper operation, parts do fail.
bigred1080, If you choose to have your vehicle diagnosed at a GM dealership, please do not hesitate to reach out. You can reach us via email at firstname.lastname@example.org. Please be sure to include your name, VIN, address, phone number, and dealership. Erica Tiffany GM Customer Care
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