Formulabruce

Found out its the same as a SLT...

Look for the width and height of the front opening where the emblem goes please, on a 2018 HD Denali, Thanks!

The other cause I found is cold solder joints caused by a switch To a steel based solder and corrosion Also the battery saver timer can short on the board around it. There was a guy on ebay selling rebuilt units with better bulbs etc. He will only take trades that have not been serviced.

On the DS rear, buy a bracket that bolts to the back of the head, and has a bolt that puts pressure on the manifold at the original hole and it will Not leak. These are all over Ebay. Its tough to get back there to install it, but it works. On the Bolts, Im with Davester, But I use COPPER never seize as well on them. Don't use aluminum never seize on Aluminum heads, you need a dissimilar metal.

Simplest first.. Do these grounds, and coat them with grease after.

There are plenty of the NP261 T cases around. Yous can be rebuilt too. Its not that tough. So, to the OP, What does 'Broke" mean? ........

David is 100% correct about the frames. They didn't make that many "HD" frames in 2000 . Easy way to tell is look at back end of it. It will be Boxed at the rear, where the 1500, and 2500 ( light duty) are just C channel. the 3500 WILL be a Boxed end frame.

This is 100% correct. At one point, I used to swap out my T stat for the summer to a 160, which worked perfect and the ac ran cooler, but after some research and testing I found my truck doesnt get above 195 unless towing. I would HIGHLY recommend a upgrade size trans cooler if you tow, the stock ones seem to be bare minimum IMHO.

05 is same as 04, same as 06, and 07 classic in 3/4 ton , 1 ton only.

There are a FEW "Black bear" tunes. They are VERY NON descriptive on what they are, and do. I will guess they only adjusted the trans shift points. Then messed with engine timing, mixture etc. NO tune will disable the 1-2 rpm up shift. Even a Brand new GMC Denali will NOT downshift to 1st when the cruise is on going down hill. ( decent control) . I am betting youll be doing a trans rebuild if you start to manually shift it if its got over 150K on it. Your 4 crew cab is Not a light truck.

Jay, 1. The Power you seek DOES come from a slow blow fuse. It is under the hood, DS in the big plastic Distribution box. It will be "MISSING". Its Square and closer to the engine. This will power up that +12 v pin at the 7 pin connector. I do not recall what its called, but its pretty obvious. 2. The reverse camera. IF your camera is "wireless" ( only has ground and hot from reverse light AND an antenna) You will NOT want it powered all the time. Why? There are folks driving around with more powerful transmitters and you will Receive THEIR feed. I drove 50 miles one day on a busy highway and all I saw was the INSIDE of a Horsetrailer that was near me on the road. This is for WIRELESS only... Wired, No issues.

Adding a capacitor ( noise suppressor) is an old trick that used to work well, and may just fix this. ( credit to Pizza) The Body control module ( all cab functions) GROUND is UNDER the truck, on the DS, right under the DS door on the CAB mount Extension facing the REAR of the truck. These ground wires need to be removed and cleaned well, and frame cleaned. After put some waterproof GREASE on it.. Did you do this ground?

My vote get some THROTTLE BODY Cleaner ( ONLY use specific Throttle body cleaner) pull off the air intake giant hose clamp, and hose, and clean, clean, clean, and back side of the throttle plate too. All it takes is a Little dirt to cause this.

The problem lies with whats called a Ground loop. The radio, for lack of a better term, is using the speakers as a ground. Pull the radio. If you used an adapter pigtail, make sure you Solder the power and ground leads. Check the ground wire size, make sure its same as power. Check the ground wire ( truck off, key out) coming to the radio, to truck ground with a ohm meter. I turn on the beep on my meter, so I don't have to look at the resistance. Probably a NEW ground wire from the chassis of the radio, to a GOOD truck ground, ( possibly one of the 2 cigar /12 volt outlets below) will do the trick. Good luck!

BCM Ground. Driver side CAB Extension mount ( just under the DS door) On the mount, facing rear are a bunch of wires grounded to the mount. Remove, clean WELL, then grease/woolwax after re installing. Cost... about Free... Still have issues? Grounds at back of engine to Firewall..