06 F350 noise after shut down

[jon dietrich]

Every time I shut the motor off it sounds like a relay of some sort stays on for about 15 to 20 seconds. I pulled the glow plug relay off as it was making the noise and it didn't shut off. Does anybody know where to start? Thank you

 

[RoyBoy]

Is it a buzzing type noise from under the hood? If you have a older PCM flash, it's normal cycling the injectors to limit rough cold starts.

 

[HeavyAssault]

Yep...WHS.