Low air alarm in 2000 Monaco Diplomat

[jackie]

This morning, I went to check on our 2000 Monaco Diplomat DP..

When I opened the door, the low air alarm was going off. I have no idea why. I started the engine, let the air come up, and it was still going off. I turned the engine off, dumped all of the air, and the alarm was still going off.

I cranked the unit up again, and drove it around the block, the low air alarm going off the whole time.

I parked again, shut every thing down, and the alarm just keeps going.

Any thoughts. I can’t even find the darned alarm to under the dash, or the fused link that powers it.

[oldave]

Jackie , you are correct , the alarm should not be sounding with the key off .
That sounds like a stuck relay to me '

I had the same alarm one time when we owned an Endeavor
It was maddening so I stopped and went looking for the cause I didn't find
the cause but I did find a relay in the front lower elect compartment
that stopped the noise when I unplugged it .
Later I plugged the relay back in but the alarm / noise didn't return and
I never had the persistent alarm again .
Maybe the relay was stuck I don't know .
On our Monaco coaches the annunciator / alarm is activated by more things than
just low air although I can't say what those other things are .
Here is a link , if it will work , that may help .

http://www.irv2.com/forums/f115/dash-alarm-wont-quit-361881.html

Ray

[JRscooby]

jackie wrote:
I got to my shop, plugged an air gage into the air system, and it has 120 psi.

I finally found my chassis wiring diagram, and found the wires that go to the alarm. They had the darned thing stuffed in the firewall bulkhead. I found the alarm, and pulled the plug.

I have good air, the jacks go up and down, and the coach drives and stops good.

I obviously have a faulty sensor somewhere. I just have to find it.to

One of my drivers called me, OOS because the low pressure buzzer didn't work. I got there in tool truck, LEO left. Driver said "Plug it back in, I'll scrape the sticker" WTF? "Broke a leaf on rear spring this AM. They found the buzzer, quit looking" Good job, hate to do spring work under a load, along side the road.

[RCL]

There is a pressure switch attached to your parking brake release button. Those switches are notorious for failing.

Dick L. 04 HR Imperial

[Roger_in_VERMON]

Note what I said was two sensors. My mechanic thought he solved it replacing one sensor only to find out he needed to replace two. He said it is confusing with all the wires but found the second sensor.

[jackie]

I got to my shop, plugged an air gage into the air system, and it has 120 psi.

I finally found my chassis wiring diagram, and found the wires that go to the alarm. They had the darned thing stuffed in the firewall bulkhead. I found the alarm, and pulled the plug.

I have good air, the jacks go up and down, and the coach drives and stops good.

I obviously have a faulty sensor somewhere. I just have to find it.to

[jackie]

Roger in VERMONT wrote:
We had the same problem with our 2001 Holiday Imperial. It was one of the air sensors. There were two.

I will go over this morning and dig out the wiring diagram and see if I can locate the sensor. I have the entire dash pulled back and see the air line from the gage going into the firewall bulkhead. If it’s in there, I will have to figure out a way to get in there.

I am also going to hook a calbrated air gage into the air coupling located in the main fuse capartment in order to see just how much air the unit has.

[wolfe10]

RE: key off problem:

Do other things that should only work with the key on work with it off-- dash HVAC fan for example? If so, start by checking at the IGNITION SOLENOID.

[dougrainer]

jackie wrote:
The gage in the 2000 Diplomat has no numbers on it, just lines. There is a line where the alarm has always cut of at. The gage reads well past that, well over 3/4 of the way around, so I doubt that low pressure is the issue.

Some of you are not listening . The alarm is going of with the key off, parked. The only way To stop it is to disconnect the battery. When you reconnect the battery, it just starts going off again.

Some of us ARE listening. IF NO NUMBERS, how do you state that it was 60 to 80 PSI????????????????????:) AND, You have other problems if the alarm goes OFF with Key off. You have an Ignition side that is HOT with the Key off. So, you have 2 problems. The air alarm is the low Pressure switch system has a fault most likely a bad air sensor. Then fix the Key OFF problem. Doug

[Roger_in_VERMON]

We had the same problem with our 2001 Holiday Imperial. It was one of the air sensors. There were two.

[jackie]

The gage in the 2000 Diplomat has no numbers on it, just lines. There is a line where the alarm has always cut of at. The gage reads well past that, well over 3/4 of the way around, so I doubt that low pressure is the issue.

Some of you are not listening . The alarm is going of with the key off, parked. The only way To stop it is to disconnect the battery. When you reconnect the battery, it just starts going off again.

[dougrainer]

Sorry, Air systems should be OVER 110 PSI. The cut off for a Air System alarm is the 70 to 80 PSI. So, the system is accurate. Your problem is inadequate air pressure in the tanks. OR the air PSI gauges are wrong and your air is over the 110. Regardless, if you show 80, that is your problem. I have never heard of a Air alarm going OFF when the key is OFF. Makes no sense as when parked and you exhaust the air system, the alarm would go off if wired for HOT all the time. Doug

[wolfe10]

If air system maxes out at 80 PSI, most likely "suspect" is the AIR GOVERNOR.

Not expensive or difficult to replace.

[JRscooby]

jackie wrote:

JRscooby wrote:
What does the gauge say?
Power to buzzer should be switched by main switch

The gage reads what it always has, between 60 and 80.

Everything works great, brakes, air ba suspension, but the darned alarm will not turn of, whether the key is on or off.

If I knew the wire that fed it electricity, I would disconnect it. Right now, I can’t even find the alarm, and I have the dash taken apart.

Sounds to me you have more than 1 issue.
First, if your system maxes out at 80 and has for a while you have a bad compressor or more likely leaks. If you have been driving like that you should be shamed.
If the buzzer is on with the "ignition" switch off, you have power getting to it from someplace it shouldn't.

[wolfe10]

The low pressure warning SHOULD come on before pressure is lowered to 60 PSI.

If you start the engine and build PSI back to cut-out PSI (assuming 110+ PSI) is the alarm still active?


Air Brake System Pre-trip Check


1. Be on reasonably level ground. Block wheels so the coach can not move even with the parking brake off.

2. Start engine and run until full air pressure is reached. Listen for the dryer to purge (about 120 PSI).

3. Shut off the engine.

4. Release the parking brake by pushing in the yellow button (make sure you don't roll, and do NOT apply the brake pedal).

5. After the initial pressure drop, the system should not loose more than 2 PSI per minute.

6. Apply the brake pedal firmly (still with the parking brake OFF).

7. After the initial pressure drop, the system should not loose any more than 3 PSI per minute.

8. With the engine off, ignition on and parking brake off, rapidly pump the brake pedal to bleed down the air supply. During this stage you should watch for the warning light and buzzer at about 60 PSI and then the yellow button (parking brake) should pop out at about 30 PSI.

9. Restart the engine and build up air pressure again. While building up pressure, check how long it takes for pressure to go from 85 to 100 PSI at “cruising RPM”. It should be less than 45 seconds.