Trailer Brakes

[dandick66]

I located the 6 pin Mate N Lock plug and tested the wires.  I verified the “blue” wire is connected to the 7 pin plug in the back.   I tested all of the other pins on the 7 pin plug and all work except the 12 volt pin.  I tested with the ignition off and on, engine off and on.  Fuse 34 in the FRB is good.  I’ve attached the drawing for the trailer plug.  Unfortunately, the picture is blurry.  The wire in question is “B” and referred to as RLTR87 Trailer ignition” and the 12 volts comes from “D”.  I have no idea where “D” is.  Any ideas?  FWIW, I discovered that my brake lights only come on with the engine running.   Not sure if that’s normal or not.  I know that car brake lights come on whether engine/ignition is on or not.  
 

[CAT Stephen]

It is normal and expected that your brake lights only come on with the engine running or when the ignition key is in the "run" position, dependent upon you braking system (air vs. hydraulic)

[dandick66]

On 8/23/2023 at 10:49 AM, dandick66 said:

I located the 6 pin Mate N Lock plug and tested the wires.  I verified the “blue” wire is connected to the 7 pin plug in the back.   I tested all of the other pins on the 7 pin plug and all work except the 12 volt pin.  I tested with the ignition off and on, engine off and on.  Fuse 34 in the FRB is good.  I’ve attached the drawing for the trailer plug.  Unfortunately, the picture is blurry.  The wire in question is “B” and referred to as RLTR87 Trailer ignition” and the 12 volts comes from “D”.  I have no idea where “D” is.  Any ideas?  FWIW, I discovered that my brake lights only come on with the engine running.   Not sure if that’s normal or not.  I know that car brake lights come on whether engine/ignition is on or not.  
 

SOLVED!
According to my drawings, the trailer charge signal is supposed to come from VC08.  However, there is no wire attached to VC08.  
                      
I found the relay and associated fuse in the RRB above the batteries.  The fuse and circuit are marked as ECM Batt.  I’ve attached photos for any other poor souls with a circa 2012 Monaco.  
 

[Dr4Film]

Confused between your post yesterday @ 10:49 am and your most recent post today in regards to the missing "charge" wire that is 12 VDC to keep the toad battery fully charged. You posted different locations and different terminology.

A better explanation needed for my feeble mind.

[Tom Cherry]

7 minutes ago, dandick66 said:

SOLVED!
According to my drawings, the trailer charge signal is supposed to come from VC08.  However, there is no wire attached to VC08.  
                      
I found the relay and associated fuse in the RRB above the batteries.  The fuse and circuit are marked as ECM Batt.  I’ve attached photos for any other poor souls with a circa 2012 Monaco.  
 

Great…so restore the improperly installed OEM circuit.  The logic…as I would need to see the schematic and not the block diagram,is …

Ignition switch must be ON (engine running or not).  Relay closes via the Ignition signal.  The auto reset CB gets power from somewhere in the back.  The 30 amp contact switches the power from the the CB and it goes directly to the trailer plug.

Now..from my vast escapades with installing brake controllers and wiring up toads and also trouble shooting brake lights.

There is NOT, an FMVSS (Federal Motor Vehicle Safety Standard(s)) for Brake Lights…other than come on when stopping.  Bill Groves (RIP) argued that his 2006 Hummer H3, had the electro hydraulic brakes HOT…as in hit the brakes….lights come on….and the electrical brain applied the brakes.  i finally sent him the print on my 2008 H3. Hummer changed the circuit.  The Hummer sites and US Gear and Brake Buddy had conflicting info….and finally…model year dependent….must test and verify.

WHY…one would ask.  Simple, the Hummer’s brakes were electric.  Drive and they work.  Tow, with switch off, on the 2008, they do NOT.  US Gear finally got prints for the early ones and up to the 2008.  SO, the US Gear came with a small vacuum pump.  You hooked it up to the Vacuum brake booster…you always had POWER brakes.  Brake Buddy, perhaps others, depended on an air cylinder…had you BLEED off the power assist…. US Gear’s brake lever (pedal) solenoid was electric…not as powerful.  So, when you bought a US Gear system and put it  in, you installed the vacuum pump.  Hit the brakes…pump comes on.  i had to wire in a Diode protected  circuit to the “motor” or power up the “brain” when my US Gear Brakes were on.  That DID also activate the brake lights.  Sit in the Hummer and hit the brakes…NADA….no brakes or lights…so if you were rolling down a hill and ignition not ON…you go NO BRAKES.  Thus BB could not make their air cylinder braking system work…and stopped selling it for Hummers.

it happens..and I am SURE GM met the FMVSS regs on the Hummer…the first run cars are inspected by the USDOT and an outside Professional (SME?) team and the GM engineers.  i used to build carburetors and know the drill.

So, there is not a hard and fast rule, to the best of my knowledge, and “it depends” as in trust but verify…

[dandick66]

2 hours ago, Dr4Film said:

Confused between your post yesterday @ 10:49 am and your most recent post today in regards to the missing "charge" wire that is 12 VDC to keep the toad battery fully charged. You posted different locations and different terminology.

A better explanation needed for my feeble mind.

The short story is that yesterday I couldn’t find the 12 VDC source.  Today, I found it.  I used the drawings from a 2008/9 Camelot since “it looked the same”.  Well, it wasn’t the same.  The 2008/9 drawings show VCO11 and 12 and F34.  My 2012 drawings don’t show the trailer plug.  When I mentioned VCO8, I should have said “label”, not drawing.  The label on the FRB door said the trailer charge was on VCO8 - it’s not.  I have since found the connection is at VCO5. 

 I traced the wire RLTR87 from the plug and saw that it went into the RRB above the battery box.  I found it went to the relay I showed in the photo.  I followed the relay wires and saw one of them went to a connector with a 30 amp fuse, marked ECM Batt (see photo).  The 30 amp fuse was blown so I replaced it and now I have the 12 VDC at the plug.  There’s even an LED beside the fuse that is now lighted.  I should have noticed it was a DED (dark emitting diode).

I hope that better explains everything.

2 hours ago, Tom Cherry said:

Great…so restore the improperly installed OEM circuit.  The logic…as I would need to see the schematic and not the block diagram,is …

Ignition switch must be ON (engine running or not).  Relay closes via the Ignition signal.  The auto reset CB gets power from somewhere in the back.  The 30 amp contact switches the power from the the CB and it goes directly to the trailer plug.

Now..from my vast escapades with installing brake controllers and wiring up toads and also trouble shooting brake lights.

There is NOT, an FMVSS (Federal Motor Vehicle Safety Standard(s)) for Brake Lights…other than come on when stopping.  Bill Groves (RIP) argued that his 2006 Hummer H3, had the electro hydraulic brakes HOT…as in hit the brakes….lights come on….and the electrical brain applied the brakes.  i finally sent him the print on my 2008 H3. Hummer changed the circuit.  The Hummer sites and US Gear and Brake Buddy had conflicting info….and finally…model year dependent….must test and verify.

WHY…one would ask.  Simple, the Hummer’s brakes were electric.  Drive and they work.  Tow, with switch off, on the 2008, they do NOT.  US Gear finally got prints for the early ones and up to the 2008.  SO, the US Gear came with a small vacuum pump.  You hooked it up to the Vacuum brake booster…you always had POWER brakes.  Brake Buddy, perhaps others, depended on an air cylinder…had you BLEED off the power assist…. US Gear’s brake lever (pedal) solenoid was electric…not as powerful.  So, when you bought a US Gear system and put it  in, you installed the vacuum pump.  Hit the brakes…pump comes on.  i had to wire in a Diode protected  circuit to the “motor” or power up the “brain” when my US Gear Brakes were on.  That DID also activate the brake lights.  Sit in the Hummer and hit the brakes…NADA….no brakes or lights…so if you were rolling down a hill and ignition not ON…you go NO BRAKES.  Thus BB could not make their air cylinder braking system work…and stopped selling it for Hummers.

it happens..and I am SURE GM met the FMVSS regs on the Hummer…the first run cars are inspected by the USDOT and an outside Professional (SME?) team and the GM engineers.  i used to build carburetors and know the drill.

So, there is not a hard and fast rule, to the best of my knowledge, and “it depends” as in trust but verify…

Tom,

There is no CB in my setup.  The relay pins are: pin 30 is connected to the 30 amp fuse in the RRB, pin 87 is the trailer battery charge wire that supplies 12 VDC to the trailer plug, pin 86 is connected to VCO5 in the FRB and pin 85 is ground (I might have pins 85 and 86 misidentified).  As you mentioned, the ignition switch must be on and it energizes the relay and it supplies the 12 VDC to the plug.  
This is the way it came from the factory as another owner of a 2012 Knight has the exact same setup.  I guess Navistar made changes and didn’t document them properly - big surprise.  

[Tom Cherry]

39 minutes ago, dandick66 said:

The short story is that yesterday I couldn’t find the 12 VDC source.  Today, I found it.  I used the drawings from a 2008/9 Camelot since “it looked the same”.  Well, it wasn’t the same.  The 2008/9 drawings show VCO11 and 12 and F34.  My 2012 drawings don’t show the trailer plug.  When I mentioned VCO8, I should have said “label”, not drawing.  The label on the FRB door said the trailer charge was on VCO8 - it’s not.  I have since found the connection is at VCO5. 

 I traced the wire RLTR87 from the plug and saw that it went into the RRB above the battery box.  I found it went to the relay I showed in the photo.  I followed the relay wires and saw one of them went to a connector with a 30 amp fuse, marked ECM Batt (see photo).  The 30 amp fuse was blown so I replaced it and now I have the 12 VDC at the plug.  There’s even an LED beside the fuse that is now lighted.  I should have noticed it was a DED (dark emitting diode).

I hope that better explains everything.

Tom,

There is no CB in my setup.  The relay pins are: pin 30 is connected to the 30 amp fuse in the RRB, pin 87 is the trailer battery charge wire that supplies 12 VDC to the trailer plug, pin 86 is connected to VCO5 in the FRB and pin 85 is ground (I might have pins 85 and 86 misidentified).  As you mentioned, the ignition switch must be on and it energizes the relay and it supplies the 12 VDC to the plug.  
This is the way it came from the factory as another owner of a 2012 Knight has the exact same setup.  I guess Navistar made changes and didn’t document them properly - big surprise.  

Mine mat have been or probably is a fuse.  Monaco was migrating to CB.  SO rephrasing that…a protected chassis power source for the charging circuit.  Yes…2012 was probably like a lot of years…what’s a missing wire here or there.  It started..we drove it off the line.  Let the dealer fix it.  If he finds an issue before it is sold, he fixes.  After sold, we (Monaco) picks up the warranty tab…

[Dbircky]

MODERATOR EDIT.  This is an ongoing discussion.  This new topic has been combined with the one that matches the question asked below.

END of EDIT

I pulled off the cover to find the pre wired connector for an electric brake controller.    The only plug I found is this 4 wire plug.   The only marking on it is the letter R.    

Two questions:

Is this the only connector for a  brake controller?   I have both the round and the flat four sockets.   The flat four has running, turn, and brake lights already working, so I imagine those are also good in the round plug 

What do you recommend for a brake controller band where do you mount it?   The ones I've put in pickups had to be mostly level to function properly.   
 

Thank you.  

Edited September 22, 2023 by Tom Cherry
Combined with former topic

[Dbircky]

Ok, I pulled off the cover under the driver side console.    There was a 4 wire square unused plug.   The only label on it is the letter "R".   Is this my brake controller plug? My Monaco was built in January 2008 if that helps.   I have both round 6 and flat four sockets on the back.   The flat four works the lights on a trailer correctly.   
What brake controller would you recommend?

I also found all the wiring including the antenna for a cb in the same area.   Those white wires all are marked with what they are, but the brake controller uses heavier gauge wires with no markings on them.   
 

Thank you.   

[Tom Cherry]

9 minutes ago, Dbircky said:

Ok, I pulled off the cover under the driver side console.    There was a 4 wire square unused plug.   The only label on it is the letter "R".   Is this my brake controller plug? My Monaco was built in January 2008 if that helps.   I have both round 6 and flat four sockets on the back.   The flat four works the lights on a trailer correctly.   
What brake controller would you recommend?

I also found all the wiring including the antenna for a cb in the same area.   Those white wires all are marked with what they are, but the brake controller uses heavier gauge wires with no markings on them.   
 

Thank you.   

OK....you ain't found what you need and if you start monkeying around, you are gonna regret it.  LOOK at the picture.

 

THIS IS THE PLUG YOU MUST FIND....and there have been many "skeptics" that did not do the grunt work and finally did find it.  That is NOT a put down...so take it as advice.  There are three or four places.  MINE was hidden (maybe the Assemblers like to do that?) the best of any...  I have the same rig....as you.

In order of Simplicity....  

Pull the cover off the back of the front dash and get a flashlight and peer down to the left (look through the windshield).  The bundle or the plug has been know to be coiled or just hanging up in the lower left corner.  

Stick you hand under the dash where your left foot is and feel UP....that is getting to the same area as looking from the top.

Crawl up like a ball and lay on the floor...move the seat back.... or maybe rotate it....Slides need to OUT.  Put you hand behind the drivers console....  That is the console with your Allison Shifter.  Where it meets the floor, put your hand behind the vertical panel.  Then start "Feeling".  If you have one of the phone inspection cameras with the LED lights...use it to see what is back there.  ALL SORTS OF SURPRISES....

Finally, the way I found mine and a qualified Monaco TECH said...They left yours OUT...you ain't got none....  So much for his SKILL set and KNOWLEDGE...

Take off the inspection cover on the Driver's console.  Put your hand behind the vertical wall....and work your hand towards where you left foot would be.  I started feeling "Bundles".  I knew it was 5.  Then when I found a bundle, I gently tugged.  MOST of them are pretty tight or have no slack.  BUT, about the 3rd bundle...the harness moved.  I worked my hand further to the front....and then felt the connector.  I then came in from the place where your left foot goes and hooked it or passed it to my other hand and pulled it out.  Had to do some "rearranging" and it was then free from the other bundles.

NOW....if you casually scrolled the first page and the second...GO BACK.  There is a DRAWING of the END of that.  That tells you WHICH wires are which.  The wires are WHITE....and there is a Dot Matrix label on them.  I never could read mine.  Then, go back to my post and follow the VOM instructions and identify each one.  NOT DOING THAT will cause you untold grief. 

The Harness, unless it DID get left out...but it was part of every Camelot and Scepter wiring package is there.  No one YET, has failed, in 2008 or 2009 Models to find it.  SO....persevere...

Tekonsha is the GOLD standard.  Buy the one that matches the needs of your trailer.  If you don't understand what you need...call them.  They will tell you which one to purchase.  You will have to be creative and come up with a bracket or brace and mount it where it is accessible....YOU DO NEED ACCESS TO THE LEVER...if you start your trailer to fishtailing, there is a distinct probablity that something bad can happen.  As WILD as it seems, a 42 Ft Camelot was ROLLED because of an Errant Cadillac ESCALADE...  YES, I knew the owner....and he sent me picture.  You NEED to be able to grab the lever and lock in the brakes...  I used to haul cattle in a horse trailer with a small pickup (my FIL was CHEAP) and I often had to lock down the trailer when they three Holsteins back there got into mischief.  I have also seen, in my rearview mirror a small TT take over a Dodge SUV....and it was NOT pretty....

Just some food for thought...

[Dbircky]

Ok, so any idea what this plug is for?   I'll keep looking for a white one.  Have been behind the dash both top and bottom and didn't see nor feel it there.   

[Dr4Film]

Tom Cherry should know since he owns the very same coach except for a different floor-plan.

Edited September 24, 2023 by Dr4Film

[TommyL]

A few years ago we added trailer brakes, I eventually found the wiring (plug ) Tom C pic shows. It was buried in the wiring harness,left side of steering wheel. Just to be sure , we tested from plug under dash to trailer plug at rear of MH.

08 camelot tag