Community Forums

Doug Patton · 12-21-2014, 04:51 PM

I have a 2004 Monaco Diplomat PDQ. When driving the coach everything seems to work well with the air system. It maintains 120 PSI but occasionally, after driving the coach and then pulling into a rest area or stopping (leaving engine running) for a sandwich, when I pull back out on to the highway the low air alarm will go off and continue to sound the alarm for several minutes. Then it quits and all works well. When this happens I check the air gage and I still have 120 PSI but have the alarm sounding for three to five minutes. Any suggestions as to what is causing this?

Stretch · 12-21-2014, 06:07 PM

I think your air brake pressure gauge should have two pointers. One is for the rear axle and one is for the. Front axle (brakes). Are both pointers above 120 psi?

Papa_Jim · 12-21-2014, 07:20 PM

The sender for the low pressure alarm is on the front air tank. On my coach the sender looks much like a small hockey puck. It may be that the two wires connecting to it have become corroded. Try cleaning them. If that solves it, coat the connections with some silicone to slow down future corrosion.

Jim

Mike Canter · 12-21-2014, 07:43 PM

Is there a Low Air Pressure warning light on the dash and if so does it light when the alarm goes off? If not then my question would be how do you know that the alarm is for low air pressure? If you turn the engine off and turn the ignition key back on and pump the brake pedal to deplete the air in the tanks then do you get a low air pressure alarm and light?

pklonn · 12-22-2014, 08:03 AM

Had the exact situation in my 04 Windsor. Once it went off for 30 minutes as we left on a trip. Watching the gauges the alamr made no sense. Turns out, at least on my coach, that the air pressure switch at the back of the "parking brake" was defective. Replaced it and have been alarm free. Now works as it should. Take a look and see if that is your problem. Happy RVing.

Poltax · 12-22-2014, 01:56 PM

I have had this happen 3 times. Each time its the air sensor by the parking brake. Mine is located in the console by the parking brake. Replaced the sensor all 3 times and all is well.

Gorlininc · 12-22-2014, 02:14 PM

Yep. It's your parking break sensor switch attached to the end of the parking brake control. In time it will only get worse. Becomes very annoying. Monaco has plenty in stock and an easy change
Merry Christmas.
Rick

Poltax · 12-22-2014, 02:28 PM

The last time it happend I was 800 miles from home and on the way home. After 30 minutes, I unplugged the wire assembly into the squaking speaker. Silence was nice.

Playtime III · 12-22-2014, 05:14 PM

How much is the part? Easy is relative. 1/2hr with basic tools? Ive been tolerating this for a while now and it just hasn't gotten high enough on the TO DO list yet.

tireman62075 · 12-22-2014, 07:24 PM

thanks to this website I found that is a very common problem. the parts man told me the same thing.
my switch was located under the park brake control. small panel with 4 screws and had easy access after removing the retaining nut's on the parking brake. there is a part number on the switch, there are some different numbered switches.
this was on my 2005 Holliday Rambler Scepter.
Good luck, it is a easy repair.
tireman 62075