Journey odd electrical problem

[Odinthewanderer]

Hi , I have a 2001 Winnebago journey, freightliner xc chassis. After being at a campground for a few weeks we were woken by a buzzing noise. With no key in ignition the backup screen was partially lit, the jacks down light was flickering, the transmission selector was blinking on & off, a buzzing from the dash area, and either the jacks down or parking brake chime was sounding. Disconnecting the chassis battery cable turned everything off. Freighliner sent me the chassis wiring diagrams, & I’ve done some troubleshooting. This is what I’ve found.

The parking brake relay in the electrical compartment above the generator is the one that’s buzzing, removing it gets rid of all the problems, I tried a new relay but no change.

When the parking brake relay is installed the neutral sense relay in the small relay panel above the engine also buzzes, removing this relay gets rid of all symtoms except the chime.

The coach starts & seems to operate normally except the brake lights don’t work & the cruise doesn’t disengage when brakes are applied. I haven’t actually driven it because of the brake lights. Installing or removing the parking brake relay with the engine running doesn’t change anything except the relay buzzes.

Thanks for taking the time to read this lengthy description. I thought someone may have had this same problem. We are currently doing some seasonal work so we don’t need to move the RV till end of December. I’m a retired aircraft mechanic & would like to continue troubleshooting on my off days. Thanks for any suggestions.

Craig

[wolfe10]

Odinthewanderer,

Welcome to the FMCA Forum.

Sounds like you have something "backfeeding" the ignition circuit.  ?Alternator? ?Ignition solenoid?

 

When this happens, what voltage are you seeing (where you shouldn't)?

[Odinthewanderer]

27 minutes ago, wolfe10 said:

Odinthewanderer,

Welcome to the FMCA Forum.

Sounds like you have something "backfeeding" the ignition circuit.  ?Alternator? ?Ignition solenoid?

 

When this happens, what voltage are you seeing (where you shouldn't)?

Thanks for the quick reply, the voltage at the input of the parking brake relay is 13.2 (key off) . With relay installed, at the backup screen it’s flickering on & off too fast for an accurate reading ( goes from 0 to 5 ). I tried removing ignition & acc relays ( no change ). It looks like the brake circuits should be powered with key off ? I will try disconnecting A+ wire from alternator.

Craig

[rayin]

This is a off-the-wall direction, but this is what happened to our MH. We stopped at a rest area for lunch. When I attempted to leave, every time I put the Allison in gear the engine died, and I lost all 12VDC  to the cockpit. I would wait 15 minutes and regained electric power. Start engine, put into gear, engine dies-lost 12V to cockpit. This turned out to be from a loose connection( 1/2" nuts) on the outside of the firewall, at the port-side  upper area where there are heavy positive and negative cables secured to the firewall, which supply 12VDC to the cockpit area.

That said, over 80% of all 12V issues are the result of a poor/missing ground.

This probably has nothing to do with your problems, but it hopefully offers some insight into other possible solutions.

[dickandlois]

Craig ! Could you pass on  a copy(Attach a Copy) of the electrical PDF file that Fleetwood sent you?

   Think you have the Allison touch pad setup - I have one of the last mechanical shift lever systems and my electrical wiring will not match your's 

Does the chime normally come on when the ignition key is inserted? or is the chime you are talking about related to low air pressure?

Need to isolate the 12 volt source feed to the items in question ! 

           Rayin mentioned a possible ground problem - loose connection, but most of the grounds in this case have 1 common ground point under the dash.

The parking brake relay in the electrical compartment above the generator is the one that’s buzzing, removing it gets rid of all the problems

The coach starts & seems to operate normally except the brake lights don’t work & the cruise doesn’t disengage when brakes are applied.

Installing or removing the parking brake relay with the engine running doesn’t change anything except the relay buzzes.

Rich

What Model Journey do you have?

               

• WKP32T
• WKP34B
• WKP36L
• WKP34BD
• WKP36GD
• WKP36LD

[Odinthewanderer]

Thanks for the replies, the model is WK36GD, last 6 of chassis j36087. i haven't had a chance to disconnect alternator yet, will try that later today. the chime that's sounding is the parking brake, normally it comes on if you put transmission in gear with parking brake on or let the vehicle roll in neutral, but is very similar to jacks down chimes which comes on if you turn key on & jacks are not fully retracted. It's hard to tell which one for sure because the relay buzzing is louder, ( i confirmed that it is the park brake chime). At freightliner's suggestion i have been disconnecting all connectors marked body builder one at a time , none of these had any effect, so i think my problem is on the chassis side. (see attached diagrams) . I have also disconnected most of the connectors that have a diode in them. Rich if you look at the diagrams it looks like the park brake relay & brake lamp relay are powered with key off ? Removing either of these get's rid of the problem. 

Thanks Craig 

 

 

 

__stnaffccw001.us164.corpintra.net_Service_Wiring schematics_D06-35775.pdf

[dickandlois]

Craig, Just open the file !  There are a number of Differences between your chassis wiring and mine. 

A quick look and the cruse control and brake light circuits are - joined at the hip ! When you press the brake peddle - the cruse is disengaged and needs to be reset manually - when you press the coast / set button the cruse sets at the new speed setting plus the chime  These  3  items you listed as having issues are in the same general area of the wiring harness have wires running outside and under the chassis also.

     The Park brake relay has issues when engine is off or running - if I'm reading your info correctly. This fact kind of leads me away from the alternator and towards the dash wiring ! Because of the proximity of the problems. Going to look at the park brake circuit real closely - Oxidized connection or wire damage ?

Tracing the wiring is a slow / tedious project and can be  labor intensive.  Think I will copy the drawings onto a flesh drive and get a hard copy printed out! These drawings are generally in the 11 x 17 in. format. I then work to trace out the circuits and color code them with colored pencils.

Your issue kind of popped  up overnight> By chance do you have squirrels or other varmints at your camp sight. The little devils love to chew on wires !

Rich.

Edited this post on 12/02/2018

For Those interested in a picture of the offending  part I attached a picture, this part was compromised due to water and dirt intrusion. Shorted the 3 internal together and caused the buzz in the relay circuit in question. The Buzz was caused by a Mechanical Oscillation caused by the shorts inside this Park Pressure Sensor. When the system was aired up or not!  In this case the part was located - drivers side near the rear axle. Part cost around $100.00 The labor finding it can be a killer! NOT All systems use this type of setup, but do not over look it.,

 

[Odinthewanderer]

Rich, it did pop up overnight, it has been raining here a lot, it could be moisture related. I disconnected alternator, no change. I have isolated where I have voltage that I shouldn’t, if you look at sheet 1 in the lower left is IGN relay, at the normally open contact there is a fluctuating weak voltage of 3 to 5 volts. I think there should only be power there when the key is on. Thee wires join together just outside the relay labeled 52c . The stray power must be coming in from one of these wires, I pulled the 10 amp fuse shown just above this junction, no change the other two are harder to follow since they go back & forth through the large connectors on sheets 1 & 2.

Craig

D06-35775.pdf

[dickandlois]

Craig, I will look at the drawing area ! I did do some editing to my reply - so you might want to reread my thoughts. You do have a few hrs. head start on me ! LOL

Rich 

[Odinthewanderer]

Rich, no signs of any rodents or chewed wires, so far all of the connectors I’ve disconnected  (a lot) have shown no moisture or corrosion. I did take my pdf to a print shop & had them printed in 11 x 17 , it makes a little easier to follow, but still confusing. 

Craig

[kaypsmith]

I didn't follow the wiring schematics, but fluctuating voltage 3 to 5 volts leads me in the direction of a control board malfunction. Possibly some oxidation on the terminal ends.

[dickandlois]

Kay, Think that is possible,but a digital meter can be an issue also. The leveling system and backup screen also indicate the low voltage. Need to find the common point for what should be a stady 12 volts.  There has to be a common point feeding the systems - cruse control is connected directly to the ECM . That is a reach ,but is a possibility.

Rich.

[dickandlois]

Craig, You mentioned Fuse Voltage - I think. Could you tack some voltage reading at the fuses, list each one that reads other then 12 volt? Then remove the fuse and see if the voltage is coming from the 12 volt bus supply  or from the end of the fuse that is  powering a system or control board. 

The only item that has an issue is the chime relay when the engine is running it buzzes. I do understand that the brake light and cruse system appear to be dysfunctional.

Rich.

Got to take time to go get a hard copy of the  wiring. 

[Odinthewanderer]

Thanks to everyone who responded with suggestions, especially Rich who must have spent hours analyzing my schematics. Long story short, after a lot of taking readings unplugging & plugging connectors, the problem was the park brake buzzer switch, apparently corrosion inside the switch shorted all three contacts together. Part # 06-31933-000 located just forward of rear axle on left frame rail.

Craig

[wolfe10]

Yes, good work, both Craig and especially Rich.

[wayne77590]

All I can say is, "Wow!" That would have cost me a fortune at a repair facility.
 

Great work you two.

[dickandlois]

Graig,  Great work!  The brain was smoked last night, so I needed some down time. 

It was wonderful to read that the issue has been solved!  The information below was where I stopped. The marks on page  1 of the drawings went right through the problem area.

After that I went into the VIM  and made up a chart of all the input and outputs to see if there was any possible items that could be connected to the sense relay coil power and you found the  the common point!    Really  good work on your end. The failed part caused a oscillation in the loop of relays. That buzz in the one relay when the the engine was running or not was caused by loop when the that pressure switch  failed.

Sent you the wiring interface info for the VIM in a PM that you can open and file with the wiring info.

The info below describes the wiring and circuit 125 F trailed off towards the VIM module (No electronics in it, just a number of relays and cross connect points)

The Camera and the jack power comes from the neutral sense relay. Body Builders connection.  Lower lift corner of page 1. Those 2 items have low voltage / dimly lite. From Circuit C 409 / white wire neutral. sense relay!  When Not Energized. From The Cab / Engine Harness - right side of page one. 

It appears the sense relay coil power is getting an unwanted voltage from circuit 125-F. That also powers the park brake relay coil ! That voltage is being supplied from pin F-1 of the cab harness. Need To Change to page 2. circuit 125-F powers pin-B of the park break buzzer switch. 

Please understand that the Chassis wiring is totally different on many coaches, but the issue(s) noted here most likely are caused by a shorted component. Diode, Relay, switch, wires or connections. The best person for the job most likely is a tech that works on system control circuits. They are a different bread and most likely work on assembly lines, production, traffic control systems, Elevators, Railroad control systems and last but not least are the techs that work for all of us. The military personal that keep all of the high tech equipment running.

Note! When the coach has a relay that is buzzing - there is a strong possibility the voltage will read low. When this happens the only way to check the supply voltage correctly is with an oscilloscope .  The waveform will a square wave or a modified trapezoid. This indicates a shorted component, causing a feedback  loop.  All the relay coils that read low or share a common 12 volt source will read the same coil voltage.  The component in this case was the park brake buzzer. All 3 contacts shorted together.

 

rich.

 

 

Edited November 27, 2020 by dickandlois

[dickandlois]

Journey odd electrical problem - Water intrusion , caused 3 contacts to short together.

This is a picture of the part that was at the heart of the problem on this coach. Freightliner Chassis. The switch is attached to the park brake system - drivers side, close to the frame and rear axle. 

There was a relay buzzing sound. The issues caused are covered in post preceding this picture. Along with the circuit numbers in this case.

Can be like looking for a needle in a haystack.

Rich

 

Park Brake Pressure Switch.pdf