11 replies to this topic

[therocky]

"Park Brake" dash warning light stays on when the brake is disabled.

Brake is surely off. Probably an air actuated switch, but any ideas where it would be?

Have a 2000 Monaco-- class A...no response from the folks there.

Thanks for any ideas.

[DickandLois]

Sensor is often located in the rear axle area.
Read this link, same problem reported on a freightliner chassis.

http://community.fmc...-warning-light/

Rich.

[desertdeals69]

The switch on mine is on the yellow valve release.

[therocky]

Thank You for your help. Think I found my switch--about 7-8" down from the knob which activates the system, at the driver's control panel.

[TBUTLER]

The parking brake alarm is going off on our coach. This first occurred when we left our campground. We hooked up the car, pulled away and everything was fine. At the first stop sign the alarm went off as I pulled away from the stop. The parking brake was not engaged immediately before or during the stop at the stop sign. I pulled over and disconnected the alarm as there was no drag on the coach so the parking brake wasn't engaged. The system air pressure was functioning fine, I watched it carefully and no indication of failing pressure ever occurred.

I just replaced the sensor at the drivers brake release valve with a new one. I have done this before and it has solved the problem. This time it didn't stop the alarm so I assume the sensor is good. I have disconnected the alarm again and now am looking for the next thing that could be defective. I guess it could be the alarm itself. How would I test the alarm to see if it is functioning properly? What else could I look for that might be setting off the alarm? The alarm sounds when I put the coach in gear and will not stop when the brake is released.

[desertdeals69]

If the circuit is completed to ground you may have a short to ground. Test the leads on the switch. Disconnect the wires and if one of them is hot with the key on and the other is not and the light is on then its not the switch. If the both disconnected wires are grounded then you have a short to ground.

[DickandLois]

Tom and Rocky. Do you have the service information for your chassis?
The problem my be a pressure sensor located on the front air tank.
After going over 226 pages of information on the Monaco wiring and air plumbing, there is a pressure sensor that feeds a signal (ground)up to the alarm circuit.
The same alarm is used for the Alternator failure, Low oil pressure, Water Temp., Low Coolant, and Low Air pressure. So do you have any lights on the dash display for these systems ?
Reference pages that I'm looking at are Page 35,79 and 226 in my information.
The pressure sensor appears to be connected to a 3/8in. orange plastic line? I do not see a electrical wire connection (may be going blind after looking for so long) and still have 8 pages to look over.
Wiring goes to terminal M7(Black and White wire) Terminal # 10. Now that is one side and I need to find the other feed(thinking its a ground connection). Now on one drawing it pictures the sensor and a wire or air line leading from the sensor, but not to any specific location.
Must admit that it makes me glad my coach is much simpler. Love a challenge though.
Will keep looking at the drawings,but have to give my eyes a little time off...

A little brake and a cold drink of tea--- All the signal circuits to the buzzer are grounds. So the Bk / White wire is the ground signal for the buzzer from the Air pressure sensor.
Power is supplied by a yellow wire, from M14 pin number 9.

So its a sensor issue or a ground issue as mentioned by Desertdeals.
So Tom I would think sensor, because it only happens when you are in gear; but because of the way things are wired it could be a short to ground. Just so many twists and turns in all the wiring.
One more long shot. There a diodes in all the ground feeds to the buzzer so the one in the air circuit my have failed.

This little text note is next to the diode array ! Diodes are covered with ITS-0117 and ITS-0118

This might be a part number D1-0100 (4PLS). It was next to the other information.


Rich.

[TBUTLER]

Wow, that is what I was afraid of! I'll try to get through this in the next few days. I thought this alarm was for other items also but since it occurs with the shift into gear as the brake alarm normally does I assumed that was the cause. There are no warning lights on the dash that light up, not the brake light or any other indicator. So I'll look at the electrical on the pressure switch and the alarm. Then I'll go looking for the sending unit on the front tank.

I don't have the chassis service manual.

Thanks DD69 and Rich. I really appreciate all the hard work.

[DickandLois]

Tom,

Just wonder if when you first turn on the ignition key, do your status lights go through a test sequence and then go off before starting the engine?

I sent you a PM with some drawings attached, hope you got them and they help.

Rich.

[TBUTLER]

Rich,

Yes, the dash status lights go through the normal test sequence, everything that should come on does come on. After starting they all go off. So the lights are indicating normal conditions but the alarm is going off. That would seem to indicate some kind of ground problem with the alarm or am I wrong about that.

I have the diagrams and have looked them over. I can't see a connection between the parking brake light and the alarm, guess that comes directly from the pressure reading to the alarm and then to the light. I do see a low air pressure light connection to the alarm.

By the way, I'm looking at the diagrams and they are for the Signature, Executive, Navigator and Dynasty. We have a Windsor. The electronic subsystem diagram is specifically for the ISC and ISM. We have a ISL. Given those difference, the diagrams should be useful for general guidelines but may not be exactly what I find when digging into the spaghetti.

[DickandLois]

Tom,

Looked at the wiring diagrams I could find for the Windsor and there is a difference for sure. Just wish they could make things a little more common between year and model coaches.

Thanks for the feedback. Good that all the light and per start sequence is operating. The same sensors and circuits that control the lights control the buzzer. They use the same ground connections, to the bulbs and then on to the buzzer. That makes one look at the dash, to see why its sounding off. At least that is the way its supposed to work !!! LOL

The more I look at the information available, the more it looks like a failed buzzer circuit and the only difference is those pesky diodes and some connections between the light ground that continues on to the alarm system. My buzzer will sound in the run position and the low air light will come on and stay on until the air pressure reaches about 70 psi. then the light and buzzer both go off.

Could you send me the normal sequence for you dash light and buzzer in relation to the air pressure reading ? And confirm that the buzzer is off or on when transmission is in neutral or comes on after putting trans. in drive or reverse ? Just do not want to over look a micro switch or relay issue. related to gear selector.

The air pressure alarm sounds for the volt, water, oil pressure excreta. there are differences between the models, but fundamentally they are more alike then different. The primary difference is in the way things are connected to the instrument panel and the needed changes are made in that area. With some differences in the senders or sensors. That generally is a difference in resistance.

I sent you the link by PM and it has some wiring info. for an 05 Windsor. Page 16 in the dash info. They are not the best I have seen, but something is better then nothing.

Rich.

[TBUTLER]

Rich,

I got your diagrams and have downloaded them. The Windsor diagrams are for different year but I think they are closest to what we have for our year. We were on the road yesterday and in the shop today at Cummins getting the engine and generator serviced so it is ready to go for next summer. We should get home this evening and then we have all the getting the house back in order and unpacking the motor home. I'll try to get to the alarm situation after I get caught up with everything that needs to be done. Give me a week and I'll get back to it, maybe sooner. I will verify the dash light and alarm sequence again. I believe that the alarm works normally when the system is coming up to pressure with the alarm going off as the system reaches about 95 pounds pressure. Then there is no alarm until the transmission is taken out of neutral and into gear. Normally releasing the parking brake will shut off the alarm but now that doesn't work, the alarm keeps sounding. I have replaced the sensor/switch on the parking brake release valve with a new one from Monaco. Unless that one is also faulty, that would eliminate the sensor/switch as a source of the problem.