1991 TC2000 Air Brake/Start issue

[Apacheglen]

Hi Everyone,
1991 TC2000 5.9 Cummins,
Its been sitting for a few months in Utah, put a new battery in, now the Air brake buzzer will not sound, no engine warnings, and it will not start, but turns over strong.

Somehow, the buzzer has something to do with starting the engine.

Where is the buzzer, and where is the air brake low pressure warning switch?

Then I need to determine how this affects the engine running?

Last year, the buzzer was intermittent, a few cycles of the ignition switch, the buzzer worked , and it started and ran fine.

Any help apprciated. I am a long time aviation mechanic and electrical tech..

 

[BamaBus]

I have a '92 and '98 with the 12valve 5.9 and if it is cranking and not starting then I have a fuel supply issue. I would loosen an injector line to check for fuel. The 92 has a buzzer under the arm rest, left of the driver. The switch is between the compressor and the engine block.

 

[magnakansas]

1994 tc2000

Uh, mine beeps with low air pressure. My buzzer noise is linked to the rear door. My bus was never a school bus, I believe was used like a parking lot shuttle bus, us government purchase in Houston as far as I can tell. Painted Air Force blue.

Any ways, the only time I have a no crank issue, low battery voltage, and the shifter NOT in neutral.

What about the fuel shut off solenoid, weak, sticky, or flat out busted?

William

 

[Booyah45828]

What you're likely seeing is an ignition switch or solenoid issue.

The buzzer is a symptom of it, not a cause. No need to find the buzzer or switch. The engine shut off solenoid, dash gauges/lights, and that air buzzer is likely fed power from the same source. None of them working shows that power isn't getting where it's supposed to be.

Might be related, might not be, but since you recently replaced the battery, I'd inspect that it was done correctly and you didn't miss a wire, or install a wire wrong. Following that, trace wires to see where you have and don't have power.

 

[mhaisten]

I also have a 1991 TC2000 with the 5.9. My bus did not come with a fuel solenoid but instead has a manual lever to turn on and off the fuel. If the engine spins and is above about 30 degrees F it starts. The 5.9 has no grid heater in the 1991 TC2000 so there is nothing electrical to prevent a start.

If the gauges and buzzers don't come on then it is the key switch or one of the wires to or from it.