Engine will not crank, brake lights, dome lights and door locks do not work

GWS13

MEMBER
2007 GMC YUKON
5.3L
V8
4WD
AUTOMATIC
210,000 MILES

Charging system light came on. I was told the battery needed charged. Charged it and light was still coming on. Once I shut the vehicle off it would not start back up. Wouldn't even begin to crank; then I noticed the door locks weren't working, no dome light, and no brake lights. Most other electrical works. Replaced battery and same results started looking at the wiring and fuses but can't find anything other than these two wiring connectors pictured. They were hanging loose with nothing to plug in to.

Monday, February 15th, 2021 AT 4:33 PM

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Can you try and reattach the picture? It did not attach and that may help.

Otherwise, if the engine is not cranking, does the dash lights work and other electrical items work when you turn the key?

Here is a guide that will get us started:

https://www.2carpros.com/articles/starter-not-working-repair

Also, we need to run through this wiring diagram and test for if the starter is getting proper voltage in order to start.

The purple wire below should have 12 volts only when you are cranking the engine and the red should have 12 volts all the time.

Let's start with this and go from there. Thanks

Image (Click to make bigger)