Help with Brake Light Issues

[gary_curtis]

I have been pouring through the electrical diagrams for my 2007 Patriot Thunder trying to trace the source of my non-operating brake lights. None of the lights operate Right, Center or Left. I have physically located fuses, relays and some of the modular connectors.  My problem is physically locating the TS1 & TS2 Terminals identified in Dwg#38070227 (attached). I suspect that they may be the backs of some screws on the back of the front run box but there is no label to confirm that.

When the hazard lights are on, the brake lights work (right, center and left) so maybe related to the Brake Relay or signal which drives the relay.  The brake light fuse is good.

The problem (see Pic) is likely around the Hamsar DLR Module...notice the scorching.  It looks as though it was replaced but the wiring is still in need of repair/insulation. I still smell hot insulation when I drive so I need to fix before a complete melt down.  it seems to have all started when the previous owner spliced an LED control module into to the dirver's side brake light wire and added some LEDs.

[Steve Huber Co-Admin]

Gary,
Not clear to me why you suspect the module which controls turn marker, and back-up lights other than the overheated wires (which obviously need repair). The hazard lights use the same circuitry as the brake lights. The hazard signal from the steering column switch has to go through TS1 to get to relay K4, fuse F2, etc. So TS1 is intact. That seems to indicate the problem is prior to that circuitry. Have you checked to see if the brake lights work when the engine brake is applied? if so, it would indicate the problem is between the brake pedal switch and the above referenced circuitry. Feel free to give me a call.
Steve
480-201-3686

[Mike Humble]

One time we had weird things going on with turnsignals and brake lights.  Shut down the coach including battery disconnects, shore power and solar.  Let sit 20 minutes and back on.  Everything worked.  This was suggested by Monaco tech.
Mike

[gary_curtis]

Mike... that was the first thing I tried because it's electric.  It displays the same symptoms even after a total reset.

Steve,

1) Can you confirm where TS1 & TS2  Terminals are located?  Once I find the TS1 & TS2 Terminals I can test and have confidence that it is not the brake switch.

2) Does that DRL module circled in the picture control the backup lights? I don't have any backup or rear docking lights either.

I've had this coach 3 months and now I know why the previous owner traded it in for a 5th wheel.

[gary_curtis]

I thought that the brake light circuit had something to do with the DRL module because the pin labels for that module indicated brake lights see Dwg 38031327

[gary_curtis]

Looking a little more at Dwg#38031327, the TS1-Terminal is identified. So if I follow output 87 of the Brake Lights Relay I should find the location of TS-1 in the front run box (see diagram).

[Eric Maclean]

Gary
DRL stands for day time running lights they are usually tied into the parking brake so that when the parking brake is on the the day time running lights are off when the parking brake is released the DRL turns the headlamps on for visibility.
The DRL is not connected into the brake light circuit .
It appears the relay and brake light circuit is functioning from what you have stated .
A wise man once told me always check the moving parts first because there the ones that fail most often .
With that in mind my money would be on a defective brake light switch.
The brake light switch should be close to the treadle valve ( under the brake pedal) first check to see if you have 12volts at the switch if so by simple bypassing the switch ( connecting the two wires together ) the brake lights should work if they do replace the switch.

I would not take those chard wires lightly though . You need to make sure that there are not shorted wires ( melted together)
And separate and reinsulate any wires that are compromised. Not an easy job but one that needs to be done the fact that you say you smell hot or burning wiring is concerning you need to address that first Lord only knows you may find your brake light fault in the process .
No one needs an electrical fire once they get going they are usually not controllable.
Hope some of this helps Eric

[Steve Huber Co-Admin]

Gary,

1) Can you confirm where TS1 & TS2  Terminals are located?  Once I find the TS1 & TS2 Terminals I can test and have confidence that it is not the brake switch.
  I agree TS1 & TS2 are  is most likely in the front run box as the majority of the components they connect to are also up front.


2) Does that DRL module circled in the picture control the backup lights? I don't have any backup or rear docking lights either.
The Module you circled is a series of terminal strips. From the top they are R Turn, L turn, Back Up, and Marker. Again they should be in the Front Run box.

The diagrams are confusing to say the least as they repeat relay #s based on location and PCB. There are 2 K4 relays related to the brake lights; the one shown on 3803127 (Front Run Box) which senses the brake pedal switch via J1-12 and feeds the  trailer brake viaM66-3. The other brake relay is K4 in the Rear Run box shown on 38070227.

Steve

[gary_curtis]

Thanks Eric,

That is good advise about the chard wires.  I think that those Relays marked DRL are just plain relays like Bosch etc. The board is a standard 4 relay board that is used in other locations in the motor home.  In the Rear Run Box the same relay board has Bosch brand relays. 

From the color of the wires and assumption that they are just connected to a relay I think that this relay is triggered by the path from the Brake Light fuse (15 Amp) through the brake light switch to ground. This signal is probably not making it to the back of the coach to trigger the brake relay. So fixing the chard wires will likely cure the problem with my brake lights and maybe the backup and docking lights as well.

[gary_curtis]

Thanks Steve,

The more I study the diagrams they make more sense. I think that TS1 Terminal is in the front run box and the TS2 terminal is in the rear run box. I think that TS1 may be shown in the photo at the upper left corner.  I am going to follow the black and white wire just above the "H" and see where it leads me.  It should go to terminal 5 of TS1 according to the drawings.

[Fred Brooks]

    Hi Gary,

   I was looking at your picture that has the oval circle and noticed that the red wire with white stripe and the orange wire just below the bottom "day time running lights" module are compromised. I think you are on the right track trying to run this issue down. Don't get discouraged and we will help all we can, Fred

[Eric Maclean]

Gary
It appears that the original burn was on the DRL board you can see the retaining screws are black and the plugs are scorched the board and DRL relays look new.
This is not surprising as the DRL relay are in use moving current to the headlamps at all times when the ignition is on a bad connection or over load could have been the original problem .
It appears that board burnt quite dramatically by the surrounding wiring Charing .
In your picture I noticed at the top of the picture what look like a row of circuit breakers the wire connector's don't look like factory connection and just to the right i see a plug with a green wire cut off.
I would start by killing the 12 volt power supply and the remove the DRL board and get a good look at the wiring behind it
As you have mentioned the TS1 terminal strip is the key junction point for the brake light switch signal check but I bet there are more answers behind that DRL board to be had in relation to your backup lights and docking lamp problems.
Take your time and replace any wire which has been scorched to the point the copper has discoloured ( turned black) as these will turn green with time and create all sorts of problems down the road the same goes for any connector's which have been hot or loose.
I know it looks overwhelming but take lots of pictures for reference and work slowly through all the wiring and you will find the circuitry starts to make sense.
When checking the wire integrity give them a stretch test remember good wires don't stretch.
Hope this helps and as Fred said we'll all do what we can to help
Eric

[gary_curtis]

Fred/Eric,

Thanks for the encouragement. It looks like a daunting task but I remember from my Electronic Tech training that there are only 2 ends to a wire.

Those DRL modules are just solid-state relay modules. They are supposed to be more reliable than an electromechanical relay but usually don't handle as much current. I can't find a part number to find the specification. In some places on the net I see H8005B and others I see H8014B part numbers used in DRL circuits. The latest Hamsar Catalog does not list them. The solid state relay modules they do list are 12 Volt, 6 Amp and 12 Amp modules even 12 Amp is half what you should use for a 15 amp fused circuit.

The top module does not appear to be being used for a DRL function. Maybe it should be an electromechanical relay with higher current capacity and someone switched it with the wrong part. There is always uncertainty when your not the original owner.

The module in the attachment appears to be wired to turn off the DRL lights if high beams are on. That's probably what's happening on the lower module circuit.

[gary_curtis]

This weekend I worked  about 4 hours inspecting and repairing the wires in the Front Run Box around the area where the Hamsar DRL Relay had a melt down. There were not many surprises except that the connector for the Headlight circuit was fried. The technician must not have replaced the connector when the original Solid State Relay had fried. I found a similar five pin connector on Docking lights board so I switched them thinking that headlights are more important than docking lights.

I did have time to follow the back/white wire to Terminal TS1.  You can see from the picture that I found it and marked it for the next guy.  It is the terminal strip that is located on the back wall, near the top, on the left side of the front run box.

Still no joy on the brake lights. Terminal 5 of TS1 did not have a signal when I pressed the brakes so it is looking more and more like the brake switch is the culprit.

1) Does anyone know where the brake light switch is located?

2) Does anyone have a part number for the brake light switch?

3) Where do you find a 5 pin connector like those used on the Intellitec relay boards?

[Steve Huber Co-Admin]

Gary,
The brake light switch is located on the brake pedal arm under the dash. Easiest way to check it is to use a needle or pin and pierce the insulation on the wire coming from the switch. Attach a VOM and see if you get 12v when pedal is depressed.
Fry's Electronics or Amazon would be my starting points for connector bodies. Really shouldn't matter much as to form factor as long as it has right number of pins. Make sure you have overheating problem solved before sacrificing a new connector.
Steve