Could it be the corrosion on the connections that is causing things not to work? Your fuse panel is really dirty, too. I'd get that all cleaned-up and clean those connections before I tried anything else.

 

It could be. I'll clean it up and see if that does anything, but mainly I was wondering if anyone knew what the wire attached to the silver pole is for since the one between fender and box is still taped up.

 

Both terminal eyelets in the first picture should probably be replaced. They appear pretty corroded, and the crimps do not appear sound any longer.

 

One of those wires looks burnt too!

 

Hey thanks for reply. It does look burnt doesn't it lol. Luckily it isn't tho, just built up grease that wiped off. I got the truck rust proofed few weeks ago and haven't got around to cleaning the bay.

Any idea what the wire could be that's attached to the silver pole tho?

 

One or both are related to the trailer 7-way plug. One is for the power pin, but I forget what the other is for, possibly for the trailer brake system..

 

I came across this post on the forum
https://www.silveradosierra.com/threads/need-help-taking-apart-fuse-box.465937/

It has what seems to be the same wire I'm wondering about connected to the silver pole. It's not the one between fender and fuse box.

Any idea what this is meant for?

Was looking at schematics and only other red black wire was something to do with battery isolator, but not sure if it's that wire.
https://www.gmupfitter.com/wp-conte....com/wp-content/uploads/2021/05/2011_LD_ElectricalPickupsChassisCabs_100813.pdf


Page A-12

Page A-70 shows the two other red/black wires that connect to the two terminals.

 

Go to Maxo16 comment click on his link and go to A-82

 

So what do the GURUs recommend to use to clean the fuse box. General dirt and grease? Or the bay in general?

I've normally driven diesels in the past and it was usually a general degreaser and a pressure washer. While the engine was running. But these beasts seem a little more susceptible to water.

 

If you are spraying inside or underneath the fuse box, then I would be using electrical contact cleaner.

For cleaning the engine bay in general, I've used a pressure washer w no ill effects on my '12. Everything in it was coated with a thick layer of baked on mud, that either had to be manually scraped off bit by bit or pressure washed off. Hose pressure just ran off. Even the alternator got it w the pressure washer, but I would not normally do that. All the electrical connectors under the hood are sealed, so water isn't a problem for them.

 

Thank you. I was planning on using a detailing brush/ toothbrush, spraying cleaning solution directly onto it before applying in the fuse box. Wiping away the grease with a clean rag.