I Have A New 2500hd Lly Gmc And Want To Install A High Idle Switch/kit. Does Anyone Have Experience With This. This is for pto application, not the cold weather warm-up idle. I am familair with that feature. Thanks.

it should already have one. there is a procedure to turn it on if you dont have the dic option on the steering wheel.

Either through the DIC or something to do with the brakes. It will be in your Duramax Owners Manual.

If you'd like to add manual high idle, a good way to do it is through the cruise control by using a pin to tap into the PCM. I have the pins available if you need them.

Do a search for the "CLICK HERE FOR HIGH IDLE PINS" post.