What is the sound I hear with key in ACC position?

[rbattelle]

I Have An 06 2500 That Also Makes This Buzzing Sound In Accessory Position

Alright, I guess I'm wrong. Sorry about that, MWilcox, many things have obviously changed for 2006. My 2003 makes no noise in ACC, but you can hear the solenoids and heater grids cycle in RUN. Someday I'll learn that 2006-up trucks are a world apart from the 2003 trucks.



Now I gotta wonder why the heck Cummins wants the injectors cycling with the key turned back to ACC when there's no chance of the engine starting in that position.



-Ryan

 

[mwhals]

Alright, I guess I'm wrong. Sorry about that, MWilcox, many things have obviously changed for 2006. My 2003 makes no noise in ACC, but you can hear the solenoids and heater grids cycle in RUN. Someday I'll learn that 2006-up trucks are a world apart from the 2003 trucks.



Now I gotta wonder why the heck Cummins wants the injectors cycling with the key turned back to ACC when there's no chance of the engine starting in that position.



-Ryan

Actually, you are correct. Now that I put the key backward to the "real" ACC position, there is no clicking or sound from under the hood. It is quiet unless I turn the radio on in my 2006 truck.



Mark H

 

[rbattelle]

Actually, you are correct.

DStevens - are you turning the key BACKWARD (counterclockwise) to enter ACC?



-Ryan

 

[DStevens]

Ryan, I Turn The Engine Off And Then Turn The Key To Acc. Position To Listen To Radio, And If I Turn Down Volume, As I Turn To Acc. Then I Here A Buzz That Lasts For A Couple Of Seconds, The Titan Makes The Same Noise When You Turn Engine Off, After A Few Seconds You Here This Buzz, I Assumed It Was Or Is The Vacuum System That Works The A/c - Heat Controls, But Dont Get Me Fibbing.

David

 

[JScans]

my 3rd gen also does it. i thought it might be the fuel pump. not sure if mine stops clickin. but everone askes me what it is

 

[CPittman]

Just a solution post for anyone else with an '03 / '04 w/auto trans and a buzzing sound under the hood. These are the only 3rd gen trucks that have a vacuum pump. FYI, the 1/8" dia. hard plastic line on my truck had a hole rubbed in it near the fuel filter canister which caused the vacuum pump to run all the time (very annoying... ) Cut the hard plastic line and slipped a short section of motorcycle fuel line over the ends. No more buzzing.