Brake Lights on MH and also Toad

[Denny Wagaman]

After several hours of TRYING  to get running lights, turn signals, tail lights and brake lights on my toad AND BRAKES LIGHTS on my 2011 Called DFT 43 I called a RV mobile tech in my town.  He was able to get the running lights, turn signals and BRAKE lights going on the Toad (2007 H3 Hummer) lights.   The Motor Home  Brake lights do not will not come on no matter if its connected or not connected to the toad.  This after checking every fuse and relay in the front bay as well as the fuses in the house and making sure that the connection with 7 wires from the MH going into 4 wires in the toad He called REV/Monaco and spent about 20 minutes on the phone checking out the different possibilities to no avail.  I believe that he is well qualified.  During this time my friend who is an aircraft mechanic as well as a commercial pilot flying for a well known airlines AND that does all work on his Prevost they both said time for REV they decided that they were both stumped.  Although my pilot friend who has the space next to mine in the garage said that he believes that there is a fuse that was missed some place.  

I sure would appreciated any thoughts on this subject.

Thanks,

Denny Wagaman,

 

[Dr4Film]

Tom Cherry is the Camelot goto person. He is an owner of a Camelot plus a moderator here

[jacwjames]

It will be interesting to see what Tom will come back with.

But I'll throw a swag at it.  Did you check the brake pedal.  I have two low pressure switches that send signal for cruise cancel and brake lights. 

[philcarrell]

There is a 5 amp fuse in the front run bay on my o8 Exec.  You may check there and see if you have one.  My toad connection harness had a short in it took me about 3 fuses to figure it out

[Jdw12345]

I would find the pressure switches that Jim mentioned above and start there, maybe this has been done, idk….

[vito.a]

What model is your motor home?

Did you check the rear electrical bay on the right side of the engine?

 

[Tom Cherry]

You guys give me more credit that I deserve.  There are several relays in this circuit....and they interact with the ECM as well as the Exhaust brake.  BUT...here goes...

We have, I think, NO PRINTS, on the 2011 Camelot...so I'm using mine....below

The Brake Switch is on the middle right of the print.  It has an output that goes to FOUR Relays RL 33; 25; 19 & 16).  RL19 is the relay that provides the SERVICE BRAKE or PUSHED IN circuit.  The VCG Brake Lights is a "Harness"  It is NOT a single wire. The Exhaust Brake circuit goes back there also....and that one is complex.

I would start with the connector called  VCG - BROWN.  That should be on the label in the FRB.  Pin 4 is the signal going to the rear.  If you put a VOM probe (set to DC V), and then to ground....when the engine is running and push on the brakes....there should be 12 VDC to pin 4.  

If NOT, then swap out Relay 19.....with a good one or steal one, 

Check the following fuses   Fuse 28 & Fuse 81; This large Printed Board Circuit is way different from the older ones or the lower as well as the UPPER food chain units.

Everything is on ONE board.  SO....two FUSES and the Relay.... 

NOW....Look at the VCD (Gray) connector.  PIN  1 should be the Brake Pedal Signal.  It MAY be a ground.... but, from the Print, it appears to be POSITIVE.  I do NOT know where it gets if's voltage from....

Brakelights.pdf

2 minutes ago, vito.a said:

What model is your motor home?

Did you check the rear electrical bay on the right side of the engine?

 

2011 Camelot and the brakes are NOT part of the RRB.  That is a simple little box, but NOTHING to do with the brakes.  The signals on the Camelot come from the Main Printed Circuit Board up front.

[Denny Wagaman]

… a 2011 Camelot DFT 43. I looked at the brake mechism and see what you maybe referring to. I have the serial and part numbers and will be calling REV about it soon.  I will be going to the REV in Coburg OR 347 miles away to have a new slide pump installed.  I will use the 4 way flashers to alert those behind me when slow or stop. I have called three RV dealers and one truck mechanic 50 miles away who say at first  oh yeah bring it in we can fix that. Then when I get into what has been done so far by a certified Mobil tech they back track. Then  they either say we don’t do chasis work, or take it back to the factory etc. etc. 

It’s beyond what I myself can do. I snuggled my under the dash well to a point as far as I could go and as I said got the serial information, and it seems to be working like it always has. When I took it out of the garage to connect the Hummer to it the brakes work. I can’t see  it well because of all the dash wiring so I couldn’t see a point of connection to activate the brake lights. 

I have a CD on the electrical wiring throughout the coach or at least I had one. I know where it was but after a quick search yesterday it wasn’t there. So this morning I will look for it again. 
 

thank you for all the comments. I greatly appreciate the, all. 
Denny

[Denny Wagaman]

All the relays work. It no brake lights. I have looked and looked for a brake switch  but so far no luck. From the brake peddle a chrome rod goes into a rubber cap  from there the rod (I am guessing) goes into a large fist size steel apparatus) that is bolted onto the exterior of the fire wall over the generator. From here I will have to do more research…. But if anyone has experience with this issue let me know. Thanks. 
denny

[dandick66]

BLUF - Start your engine and see if the brake lights work.  
 

I have a 2012 Diplomat, so the wiring, etc is similar.  I couple of months ago I was trying to locate the connector for the auxiliary brake controller.   I found it and started testing the wires.  Everything checked out except for the brake light input.  I couldn’t figure it out, then I discovered that the motorhome had to be running for the brake lights to work.  I was surprised at this, since the brake lights come on when you press the pedal on “regular cars” whether the key is on or off.  
 

[Ivan K]

3 hours ago, dandick66 said:

BLUF - Start your engine and see if the brake lights work.  
 

I have a 2012 Diplomat, so the wiring, etc is similar.  I couple of months ago I was trying to locate the connector for the auxiliary brake controller.   I found it and started testing the wires.  Everything checked out except for the brake light input.  I couldn’t figure it out, then I discovered that the motorhome had to be running for the brake lights to work.  I was surprised at this, since the brake lights come on when you press the pedal on “regular cars” whether the key is on or off.  
 

Good point, I think it was assumed that there is pressure in the tanks. Pressure switches need pressure, I don't however need to have ignition ON for brake lights to work.

[jacwjames]

Here is my brake parts page, it doesn't show the brake switches but they are on the back side.  In my case I have to remove a large plastic cover to see them.  They are shown on my chassis wiring diagram.    https://revrvparts.com/item-detail?itemId=68684&organizationId=9

IRV2 had a thread on this that is similar to your problem.  https://www.irv2.com/forums/f115/brake-pedal-pressure-switches-587433.html

1 Brake Pedal.pdf

Edited December 16, 2023 by jacwjames

[dandick66]

2 hours ago, Ivan K said:

Good point, I think it was assumed that there is pressure in the tanks. Pressure switches need pressure, I don't however need to have ignition ON for brake lights to work.

Now you have me thinking… I don’t know if I had pressure in the tanks or not when I made the discovery.  I will check it when I do my next fast cruise at the end of the month.