Hello all, first post, and first problem. Have had my truck about 3 mo. and love it. Took the family out riding today,and at a stop light heard a buzzing sound. I thought it was comming from another car beside me so I paid it no mind. Then while at Lowes I heard it again- Got out popped the hood, and there it was buzzing like all get out. Its a small black box on the left of the firewall right behind the battery. (left side standing in front of the truck).
It buzzes for about 10 sec. then stops for about 5 sec. then starts again.
It also does it when you turn the switch before the truck cranks.

I hope that I have splained so someone will understand,and tell me what it is
I also want to tell everyone how much I enjoy reading and learning about these trucks on this forum. You guys are sharp.. Thanks

 

What you hear before you start it is the fuel pump and/or grid heater. I dont think that you would be able to hear it while it is running though. Fill in you signature so we know about your truck and how to better help you diagnose the issues.

 

thanks WL.. I will

 

Found the problem. It was the vacuum pump. Seems that the vacuum line comming from it had a small leak. Pump was running almost all the time trying to keep up. Thanks..

 

Dang-you found the problem before I could help you! Was going to say the vacuum pump-mine did the same thing, due to the fact that the lines coming from it are thin plastic, and tend to rub on things. That little pump makes a heck of a noise, don't it!

 

Yelp, it sure does. It had me worried for all of about 12hrs. Went back to it today to take one more look. Traced the little plastic line out to see where it went, and there it was a little crack in the line, put my finger over it and the noise stopped Spliced a short peice of vacuum line, and it's all good

 

Thanks for the info guys...this is why this site is so great! Been noticing this sound for a few weeks now and just remember to search for it as it was getting very annoying in the recent days. After reading this post I decided to check out the hose that runs from the vacuum to the dash to the drivers side of the engine compartment and I found a hole worn through the plastic hose. I fixed that and now the buzzing sound is gone!