[DanielUribe2v]

Recently my 94 Gt has been making a weird buzzing sound. The sound, sounds like it’s coming behind the radio/center vents/dash. It has a different pitch depending on how fast i’m going (loudest being idle). Also when i’m at a light and pressing my brakes, the buzzing sound seems to be louder and same goes for when I turn on my headlights and ac. I have no clue what this could be, maybe a bad relay. I’m not sure, please help. Thank You.

 

[boostup89]

So your saying the sound changes with differences in engine vacuum?

 

[DanielUribe2v]

So your saying the sound changes with differences in engine vacuum?

yeah once i get up to speed the buzzing is either gone or very minimal, i’ve checked my relays/fuses in the engine bay but not under my steering wheel yet.

 

[HYBRED]

It could be a vacuum leak at the hvac controls. You could unplug the vacuum source under the hood on the vacuum tree to see if it goes away.

 

[DanielUribe2v]

It could be a vacuum leak at the hvac controls. You could unplug the vacuum source under the hood on the vacuum tree to see if it goes away.

where is that exactly, sorry i’m new to mustangs

 

[HYBRED]

The vacuum tree is over by the brake booster. There will be a small vacuum line from it running along the firewall and will enter into the firewall by the A/C and heater core connections.

unplug it at the vacuum tree.
Be careful, it’s probably brittle.