I've got a 97 F150 with the 5.4. Yesterday I drove home from work, pulled into the driveway and shut it off. As soon as it shut down, I heard a buzz coming from under the dash. I inserted the key and turned it to the point right before it turns the motor on, and the buzzing stopped. removed the key and it started buzzing again. It buzzed for about 10 seconds then went away. I was late for some evening activities, so I left it to look at later.

So today I drive to work and all is well. went to lunch, returned to the office and when I shut it off at the office, I heard the buzzing again. the noise was coming from behind the data link connector. I stuck my hand up under the dash and felt around and felt a small square object that was vibrating pretty good - I am pretty confident that it was the source of the buzzing. After maybe 15 - 20 seconds, the buzzing stopped.

I got my phone out and took a short video which shows the location of the culprit. Can someone help me identify exactly what it is? And why it would be buzzing like this? Truck starts and runs perfectly, but would like to nip this at the bud. Any help is greatly appreciated.

 

Can't get the video to work on my phone

 

Hopefully this will work...

https://youtu.be/QeBp4S1-A1k

 

I believe that's a module, can't really tell how many wires are on the connector.

I'd look at battery, and powers and grounds to make sure everything is healthy.


Modules, and relays can buzz when they're cycling in low power, or coming in and out of the voltage limits