Weird buzzing

[Lbickham]

I just got the bus insulated with spray foam insulation and now I have a weird buzzing sound like an alarm. It's not low air or rear door, both work and have a different buzzer. There are no warning lights on and bus runs and drives normal. Pulling the acc fuse silences it. I took out seats and ceiling panels before insulating, and no buzzer. I've read somewhere about a window/door alarm? Is there a way to bypass it besides pulling the acc fuse, which causes abs light to come on?

It's a 2001 International/Bluebird with an at and air brakes

[Carytowncat]

Parking brake switch not fully disengaging? I had to disconnect my pb buzzer. Good luck!

[Piersg]

Are your roof hatches fully closed?

[Lbickham]

It was the roof hatch. There has got to be a way to disable/remove the hatch and rear door alarms. How is it done?

[Piersg]

I think it depends on what kind of system is in place. In my case I took out all school bus related wiring (flashers, stop arms, buzzers, lock out, air hoses for the stop signs, etc.), and I left just the original bus wiring. That had the added bonus of killing the vampire drain I had on my batteries, plus it is a lot easier to troubleshoot now.

[birdbus]

Hi,

I have a bluebird short bus, and the buzzer alarm in the fuze box wont go off.

In the past I have had this trouble, and it has been the emergency hatches. This time they are securely closed.

I am wondering what else it could be....... I was an earlier post about a parking brake - Would the parking brake make the buzzer go off?

I finally had to disconnect the positive wire at the buzzer to make it shut up.

But I am worried that my bus might be trying to tell me something......

Any insights?
Thanks!
Hailey

[Robin97396]

Usually when the buzzer is sounding off it means the bus interlock system has been activated. It's a safety system built into school buses. Hatches also cause the buzzer to go off. Locking the back door will cause the buzzer to go off because escape exits can't be locked when there are kids in the bus. The door being open will cause the buzzer to go off too.
Usually you can't start your bus if the interlock system has been activated. It looks like everything is ok, but the starter won't engage. I'd try opening and reattaching the hatches and door locks to make sure the switches are all working proplerly. If one of the wire from a safety switch has been accidentally knocked off, it activates the interlock.
This happens one or two times a week across the country. It's usually a hatch not reconnected correctly.
Not to scare you, but when I find my hatch disconnected I realize it means someone opened the hatch from the exterior. Those hatches don't unlatch themselves. Some people actually have the hatch removed and skin the hole over with sheet metal. It's also popular to put an exhaust fan in the hatch hole sheeting.

[Lbickham]

Ours was the child safety system. We just cut one of the wires, so no power.

[Robin97396]

Yeah, the interlock system seems to be set up a little different in every bus. Maybe there's a pattern but I don't see it. You can try to reconnect the cut wire, or some people say you can ground the cut wire to the body of the vehicle and it works.
There are videos on youtube showing show people have disabled the entire interlock system on their buses.
Then again a few months ago there was a video of a 4 year old child opening the rear door of a bus while it was moving and falling out, apparently because the buzzers were disabled.