You know when you turn the key clockwise and there is a buzz when glow plugs are powered up or the buzz when seatbelt is not latched or when a door is not closed. Well the same buzz happens every time I press on the brake pedal when driving. Sometimes loud sometimes not sometimes alternates at a little slower than turn signal frequency. Have no idea but it sure is annoying. Any hints?

Close the door, buckle up then turn the key to glow. There shouldn't be a buzz.

Sounds like a bad ground.

Sixto
87 300D

Hmmm, there is a buzz and it's always been there since I've owned the car. That's what I get for buying a car from an electrical engineer. I think his tool box consisted of red high temp silicone, crazy glue, zip ties and 1 chanelock pliars. You wouldn't believe what he tried to "repair" with those. ..and proud of it too!

I had a similar problem. I disconnected the seat belt buzzer about eight years ago. Sometimes the seatbelt light comes on randomly, but I can easily ignore that.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

That's what I might do. Do you recall where the buzzer is?
I pulled the cluster and didn't see it and the buzz was so loud i couldn't tell where it was coming from. How did you disconnect it?
Thanks to both of you guys for responding!

You did not mention the year and model of car you have. In my 84 300D I got tired of hearing the buzzer and unplugged it. If I remember correctly, it was small aluminum box that plugged in about where your left knee would be, but you need to remove the cover under the dash to see it. However, after I unplugged it, the dome light no longer worked, so I plugged it back in.

__________________
85 300D 75K Anthracite Grey 0-60 in 13 seconds **For Sale**
84 300D 333K Black (The Velveteen Rabbit) 0-60 in 14 seconds
00 Toyota Sienna 208K (Sold)
15 Subaru Outback 43K
11 Subaru Outback 67K
98 Ford Taurus 100K (Gertie - Was Grandma's - drove it to church and shopping - really) Daughter's car now.
30 Model A Ford 2 Door Sedan (Sold) 0-60 in . . . Never reached 60

My car is a
1995 E300D

Low brake fluid warning? If not, you have an electrical fault in the buzzer circuit that is somehow activated by pressing the brake.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

On my car at least, the seat belt buzzer gets its power from the kickdown switch plug....my seat belt warning system didn't work....I was testing the voltage from the kickdown switch plug and it started working again....there was some corrosion built up inside the plug....once cleaned its been working perfect....

The only thing that is controlled by the brake peddle is the break lights and cruise control amp....when the peddle is pressed....it sends 12v's to the lamps and breaks the ground to the cruise control amp...telling it to shut off......the ground for the brake lamps is in the trunk....

I would go around and clean all the ground points....

__________________