06 sierra 1500 electrical problem

[Whitney Ray]

Problem was intermittent- door locks engaging, power windows work/don't work, ac sometimes wouldn't blow cold etc.

 

Now, no power locks/windows at all.  Radio won't power on.  All dash gauges do not work.  No cold ac.  Truck starts and runs fine.

 

I've checked all the fuses visually and with a multimeter. And all are fine.  Checked most grounds.  1 was iffy (passenger side engine block so I ran a new one by splicing.  Didn't help.  The other block to firewall looks possibly suspect but I can't get to the bolt to remove. Other grounds look kinda old but not worn.  I can not get the battery ground bolt off as it's rusted on so maybe that's an issue 

 

Any other suggestions.

[Whitney Ray]

I should add the battery and alternator were tested and checked out fine 

[Sharpz]

sounds like you already know the issue.

a corroded ground may very well be your problem, but you need to get them cleaned up to eliminate that possibility.  You can test areas by adding an inline ground.  For instance on your fire wall where you cant access the bolt to check...... you can splice a wire mid field and find another spot on the fire wall to ground it there, creating another ground anchor.  This will eliminate that as a problem. 

[dna9656]

When electrical gets weird it's almost always a bad ground. There are pages in the Factory service manual that show where the grounds are. Check around the different forums and you'll prolly find the data.