Recently purchased a 2004 Sierra 1500 crew cab with 49,000 original miles from a one owner veteran here in south Florida. Truck runs great but has an ABS and brake system light on, sometimes loses power randomly then runs fine and the volts keep dropping below 14 when the truck runs for a bit. Also the ac goes from cold to warm. Has a new alternator and drive belt so I’m thinking it’s a bad ground? What would you do to test this? Also, the radio comes on but no sound!
Well Jim have histories of bad ground wiring. What you have to do is get a wiring diagram of all the grounds and then test them with a meter. Or you can randomly look around and see if the bolts have gotten rusted where they both to the frame or if any wires have gotten cracked or if any connectors when you unplug them are all green inside meaning their corroded
I’ll try this first! Thank you 🙏