The beep that doesn't .....

[Ray Davis]

OK, so this one is a bit weird, and had me on the phone with both Marathon and Prevost tech support this weekend.


We arrived with the coach to Lake Havasu RV Storage on Saturday afternoon, the new home for our bus (for awhile). I'm dealing with trying to figure out how to dial-down the inverters, as we only have 20A power there, and I didn't want to blow the circuit. The same circuit handles the power doors!

Anyway, Kathy mentions a "clicking" coming from the dash area. Almost sounds like a turn signal, but if you listen very closely there is a faint beep sound (really faint).

Well, to make a long story short, we finally determine that this is coming because I had neglected to set the parking brake. When I was parking I was being guided by the manager, and a tech on a scissor lift who was verifying clearance as I drove into the garage. Because of their directing, I just missed putting on the p-brake (yeah, a bad thing, I know).

Earlier in the week, I had done similar, but there was an audible beep when the p-brake was off. Not loud, but audible.


SO, the reason for the post here. What would cause the p-brake warning beep to die out? Is there something obvious that I should look at replacing? I would personally like a very loud beep if I forget the brake.


Thanks in advance,
Ray

[Ray Davis]

So, maybe I can ask this in another fashion.


Can someone show me a URL to a Prevost wiring document, which shows me the parking brake warning circuit? I'd like to track down where/what is involved with this circuit to try to determine how to fix this warning beeper.

2001 XL2 chassis


Thanks,
Ray

[Sid Tuls]

Hi Ray, after reading your post I went to the bus barn and check mine. It just keep beeping until I engage the parking brake it wasn't a loud beep but it was continueless. Ray you beat me in miles Judy and I put on 51,40 in the last 3 weeks. Had a great trip to New Mexico,Texas,Brandson,Ne back home. Hope you enjoy your new coach.

[stevet903]

Ray is this what you are looking for?

http://technicalpublications.prevostparts.com/pdf/D060921p7_2r3.pdf

If not go here and enter the right info for your coach...

http://technicalpublications.prevostparts.com/en/wiring.asp


Hope this helps.

Steve

[Ray Davis]

Thanks Steve,

I haven't exactly found what I want, but this is in the right ballpark. Thanks!

Ray

[hhoppe]

Ray: "Buses run fast especially down hill out of gear with the brake off."
When distracted while parking it is easy to leave the seat with the park brake not set. In our cars the transmission Park is our automatic safety. with our busses no such help. I've done it a couple of times and Shirley hears the beep that I can't hear. Let us know what you come up with.

[Ray Davis]

Anybody there more familiar with Prevost schematics. In particular I'm looking at http://technicalpublications.prevostparts.com/pdf/D060921p8_1.pdf which looks like it's pointing to the parking break alarm area.

However, I don't see the alarm.

Also, there are several connections which end in a tri-angle shaped object with RS or FS in it. What does the RS/FS mean here?


Thanks,
Ray

[stevet903]

FS is the ground stud in the front compartment, RS is the rear.

If you look in the list of documents there is a CODE section that will help to decipher the wiring diagrams. The CODE - WIRING KEY that I looked at was located at:

http://technicalpublications.prevostparts.com/pdf/D060994pk.pdf

There are also sections for connectors, circuit numbers, and circuit breakers that may be helpful in tracking this down.

Steve

[stevet903]

I don't what the serial number is for your coach, but it looks like the "Piezo Park Brake Not Apply" buzzer is on the Tell Tale Lights Module diagram.


http://technicalpublications.prevostparts.com/pdf/D060994p23_1.pdf

It looks like the parking brake switch is grounded when the parking brake is off, and the NOR gate triggers the buzzer if the ignition is off and the parking brake is off.

Steve

[Ray Davis]

Thanks Steve, I'll check that one out.


Harry, I've tried to be very attentive about setting the p-brake, make sure I see the P icon on the dash board. It just happened this time, I had two guys squawking to me, guiding me into the garage, and I missed that step (not a good thing, for sure).

But, the beep is getting weaker, as it seems that something must be going out. I hope I can get a determination on what I need to replace.

Ray

[stevet903]

Ray - I hope you are sitting down ....

From the diagram it looks like the buzzer is part of the tell tale assembly since I don't see any connections to it outside of the module. If that is the case, you may need to replace the module (unless the buzzer can be removed and replaced from the module - the Prevost parts diagram does not show this, and I have an 89 without this feature so I can't look at it)

The bad news is that they are very proud of this module...

TELLTALE MODULE ASSY Up to SN 7-9096 Model MTH-40, MTH-45, MTH45S

562907 MODULE 37 TTLT XL2 $473.12

or

TELLTALE MODULE ASSY Starting from SN 7-9096 Model MTH-40, MTH-45, MTH45S

563333 MODULE, TTLT - MULTIPLEX (CPA) $1,661.88

[Ray Davis]

$1600!!! I don't think I'll be replacing that anytime soon.

Where did you come up with the parts mentioned. I was looking at

http://technicalpublications.prevostparts.com/pdf/D060921p23_1r19.pdf

and it appears they show a "piezo parking brake not applied" which seems to be the beeper?


Ray

[stevet903]

I would agree that the piezo in the diagram is what you are looking for. You can access the online parts catalog by going here:

https://order.prevostparts.com/scripts/wgate/yw20/!?~language=EN

and clicking on the P@RTner Electronic icon. You need to register to get access (contact Vicky Tremblay at (418) 654-0174 Extension 227).

Once you get a part number from P@RTner, you can click on the Available icon and get pricing and availability.

It's a painful interface to use, but there is a wealth of information there.

Steve