07 2500HD 6.6L Brake Light Out

[Beaner81]

I just bought an 07 2500HD Duramax and the right brake light and blinker dont work. I swapped bulbs and checked the fuses on drivers side dash and under hood drivers side, all looks ok but it still doesnt work. No voltage at the bulb. Is there another fuse somewhere I am missing?

[777stickman]

Not sure with your '07, but my '98 Sub rear lights are in a circuit board that fails occasionally.

[j cAT]

Originally Posted by Beaner81

I just bought an 07 2500HD Duramax and the right brake light and blinker dont work. I swapped bulbs and checked the fuses on drivers side dash and under hood drivers side, all looks ok but it still doesnt work. No voltage at the bulb. Is there another fuse somewhere I am missing?

since the one side is out follow the wires back from rear fixture to the rear junction block. this is where it usually gets damaged/open.

[Beaner81]

ok found it, under the fuse block in the engine compartment there are 5 plugs. One of the plugs has 2 of the 4 clips that hold it up to the underside of the fuse block broken so it was settling down. Found a replacement plug for $20. Now I just need to find 1 of the 2 clips that holds down the fuse block without buying a whole new fuse block.

[j cAT]

Originally Posted by Beaner81

ok found it, under the fuse block in the engine compartment there are 5 plugs. One of the plugs has 2 of the 4 clips that hold it up to the underside of the fuse block broken so it was settling down. Found a replacement plug for $20. Now I just need to find 1 of the 2 clips that holds down the fuse block without buying a whole new fuse block.

just be careful with these small wires. the wires under this fuse block go every where. surprised , with your vehicles age , you have issues here. my vehicle I had a rodent nest under the fuse block . others have had 4wd issues, and fuel guage because of wires/connectors broken there........

I am surprised you had to go that far back.

[Beaner81]

So my diagnosis of the original cause is that 1 of the 2 large grey clips that hold down the fuse block was missing allowing the back of the fuse block to raise and lower a little. The 4 tabs on the plugs dont actually clip onto the fuse block but sit in grooves on the under bracket below the fuse block holding it up agains the bottom of the fuse block. My thought is that the fuse block moving up and down allowed 2 of the tabs to fall out of the groove and get pinched and eventually broke. now with 2 tabs missing the side of the plug it pulls away from the fuse block enough to break contact.
Again I just bought this truck so I don't know how long the clamps have been missing but I am fairly confident once I replace the plug and find a clamp to hold the fuse block down this will not happen again, until the rodents move in...

Thanks for the help

[j cAT]

one forum member removed the uper intake manifold. when this was worked he put stress on the wire harness and broke some wires under the fuse block.