Electrical issues

[Jbendris]

2017 l5p duramax. Replaced both batteries and now have all sorts of electrical issues. Truck runs fine and starts without a problem. Driver side headlight went out, radio does not turn on except for back up camera when put in reverse, air/heat does not turn on, digital heads up display not working , drivers side blinker flashes extremely fast while right side does not work. Cargo lights will not turn on and usb ports not charging. Any ideas?? All gauge clusters working appropriately

 

[2004LB7]

sounds like a loose ground but I'm not familiar with where they are on that year

 

[TheBac]

....and you've already checked all fuses and relays and they are all in good working condition?

 

[Ron Nielson]

Download the Electrical manual here https://www.gmupfitter.com/wp-conte...Builders_Manual_Service_Manual_2017_en_US.pdf

Look for the ground circuit for that headlight.

 

[Rdomeck]

I would try disconnecting both batteries. Get a small jumper wire and connect the positive and negative terminals together and let that sit for an hour or overnight. This will discharge all capacitors in the truck. Reconnect and maybe clear all the codes with a scan tool.