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LongDogRanch · 04-04-2015, 01:18 PM

OK. I realize this has been somewhat discussed before but I have two specific questions and would appreciate some input on this one.
First, we have the toad's factory lights wired in sync to the motorhome's and , generally they work well. That is, with the exception of the brake lights over riding the turn signal lights when the supplemental brake system in the toad depresses the brake pedal. I understand why this happens and I know there are wiring harnesses that can resolve this, etc. But, assuming we want to keep the existing wiring harness (it was already on the vehicle when we bought it from a dealer) what is the best product to install in the toad's electrical system that will resolve this problem?
Second, with the understanding that there is a wire that exits the brake control module under the toad's dash and it goes to the brake lights, is there any reason that I couldn't install a simple on and off switch in line on that wire? That way it seems I could turn the toad's power off on that single wire to the brake light allowing the motorhome's power to illuminate the toad's brake light bulb in sync with the motor home's brake lights. Then, when we unhitching and want to drive the toad I could turn the switch back to the on position so that the toad's electrical system would activate the brake lights as per normal.
Just wondering what the current thinking is on this issue. Thanks in advance for any suggestions.

BFlinn181 · 04-04-2015, 02:52 PM

Installing a switch in the brake wire from the foot pedal would be simple, but if you don't turn the switch back on, you'll be driving without brake lights. You could install a simple buzzer in the circuit, so that when the switch is off pressing the brake pedal will buzz. Since no one rides in the car while under tow, it won't be heard but would remind you instantly to flip the switch back to normal when not towing. Just a thought.

wa8yxm · 04-04-2015, 03:08 PM

Modern cars are made with the brake light circuit powered by the portion of the fuse block assigned to BATTERY

There are two other sections to the fuse block.

One is IGNITION (only live when engine is running)
and another is ACCESSORY (you can figure that out)

Simply figuring out how to move the power source from BATT to ACCESSORY or IGNITION sections of the block will fix it.

AND... IT will AUTOMATICALLY turn the brake lights back to normal operation when you start the car.

(This is the switch described above which you have to remember to turn back on... Only I replaced the add on switch with the IGNITION switch.. Can't drive if it is not on).

dpinvidic · 04-04-2015, 04:13 PM

Most brake light switches are a single wire which gets grounded when the brakes are applied.
You can install a switch In Series which would inhibit the wire from being grounded.

However, this also kills the center brake light....so not recommended.
Regards,

Dan

JJT · 04-04-2015, 05:19 PM

A couple of thoughts other than the above mentioned. You might be able to just pull the brake light fuse on your toad, remembering of course to put it back in when you disconnect. Secondly, if your supplemental brake system on your toad is inertia controlled, you should be able to adjust the sensitivity on the brake unit so it's only activated under moderate to aggressive braking, not just normal braking or slowing. Plus once stopped, like waiting to turn, it should not be applying your toad brakes, even if you still have brakes applied on the coach.

The switch you mention should be easy if that's what you choose

Scottybdivin · 04-04-2015, 05:29 PM

ETrailer has a video of how to do this, using a Roadmaster relay kit. You have to splice in a relay to the wire coming off the brake light switch and run a wire to the "ignition side" of the fuse box. This allows the brake lights to be active only when the ignition is ON. On my F150, you need to be a 3 armed monkey to get the wiring coming from the brake pedal switch. So far I have just rolled with the brake lights overiding the turn signal. The coaches turn signals are huge and are unobstructed by the tow vehicle.

Quote:

Secondly, if your supplemental brake system on your toad is inertia controlled, you should be able to adjust the sensitivity on the brake unit so it's only activated under moderate to aggressive braking, not just normal braking or slowing. Plus once stopped, like waiting to turn, it should not be applying your toad brakes, even if you still have brakes applied on the coach.

This is my situation. I have the settings to where the toad brakes are only applied on moderate to severe braking. It is not applying the brakes while stopped, waiting to turn.

LongDogRanch · 04-05-2015, 01:40 AM

Thank you all for your comments.
As for the switch, I also think it would be fairly easy to do...except for all the fun of working up under the dashboard if that's where I've got to be working. But, it may be worthwhile. At the same time I've kind of wondered if the brake control module will detect that there is no electrical draw on the circuit when the switch is thrown and the pedal is depressed and therefore sends a "failure" message to an on board sensor that ends up triggering an idiot light or some failure message on the dash? Probably won't know the answer to this unless I try it. If it doesn't do this then, as mentioned, the biggest challenge will be remembering to re activate the circuit when driving unhitched.
Wa8yxm..I'll look into this as a possible alternative. Seems to make sense. Thanks for your input.
JJT..agree, the fuse also seems reasonable. Unfortunately I seem to recall something on a GMC Terrain thread about that fuse being tied into some other item on this vehicle that gave the owner a problem. You triggered my memory and I'll go back and try to find it. As for the sensitivity of the brake system, yes, it is adjustable and it isn't an issue once the pedal is released....like when you're sitting at a stop light waiting to turn. Good point.
Scottybdivinn..i haven't grown my third arm yet.....I think that's part of the reason I question what others have to say about it...Having done enough work on cars over the years I agree that working up under the dash board can be a real pain. Ugh!
Again, thanks.

wa8yxm · 04-05-2015, 05:20 AM

Quote:

Originally Posted by dpinvidic

Most brake light switches are a single wire which gets grounded when the brakes are applied.
You can install a switch In Series which would inhibit the wire from being grounded.

However, this also kills the center brake light....so not recommended.
Regards,

Dan

NO THEY ARE NOT... THE switch does not ground.. if that switch ever grounds then the fuse blows and you have not brake lights.

DOOR switches ground

Brake light switches either pass power or do not, but they are hot lead side switches.. That is how your cruise control can sens them (Open switch 12volt across switch

Blown fuse,Burned out brake lights or Closed switch =no voltage across switch.

LongDogRanch · 04-06-2015, 05:23 PM

Well, the final verdict (for now anyway) is that we are not going to do anything further in terms of wiring. In other words, recognizing that the toad's supplemental braking system typically applies pedal pressure for a few seconds we are going to see how it all goes by leaving the wiring just the way it is. The blinking turn signals on the MH will be the primary turn indicators for the few seconds that the toad's pedal is depressed and the toad lights are solid until released. When the toad system isn't applying brake pressure the blinkers will work in concert with the MH. Since the supplemental braking device is an inertia based system I'm starting to feel OK about this idea. Maybe someday when all my other projects are caught up (sure), I'll cut into the wires and change things. In the meantime no change. Thanks to all for your comments.
Safe travels!

Dutch Star Don · 04-06-2015, 09:46 PM

For me, I gave up on trying to wire into vehicle system after three toweds. I just run the four wire harness along the frame and insert the new smaller style (flat base)taillight bulbs into the OEM lenses. No more, issues, no draw on the towed.

ShapeShifter · 04-07-2015, 04:22 PM

Quote:

Originally Posted by Dutch Star Don

I just run the four wire harness along the frame and insert the new smaller style (flat base)taillight bulbs into the OEM lenses. No more, issues, no draw on the towed.

But if the add-on bulbs are in the same reflector cavity as the toad's factory brake bulbs, the light from the brake bulb can still override the turn signal light, making it hard to see the turn signal flashing when the toad's brakes are active. Running separate light bulbs eliminates some of the issues with tapping into the toad's wiring, but does not necessarily eliminate this one.

FIRE UP · 04-09-2015, 01:12 PM

Quote:

Originally Posted by ShapeShifter

But if the add-on bulbs are in the same reflector cavity as the toad's factory brake bulbs, the light from the brake bulb can still override the turn signal light, making it hard to see the turn signal flashing when the toad's brakes are active. Running separate light bulbs eliminates some of the issues with tapping into the toad's wiring, but does not necessarily eliminate this one.

EXACTLY!
This is why I've never been a fan of adding extra bulbs and sockets to an already crowded tail light housing. Not many, if any, manufacturers of those tail lights put in a "partition" to separate the stock tail light bulbs from any AUXILIARY bulbs installed, in the same housing. So, what you end up with is, two bulbs, both displaying different intentions, in the same housing, usually within an inch of each other.

And, if your sun is at your back and, you're following a toad displaying that scenario, and the motor home driver is driving in crowded freeway or, city street conditions, then his/her intent of a turn could quite possibly be not noticed. And that could be a potential for disaster if he/she is slowing, has signaled but, the following driver cannot differentiate the brake/turn signals and starts to pass etc. I'm sure the scenario is fairly rare but, could happen maybe for frequently than we think.

To the OP,
I did just exactly what you're thinking of. I did it on our '04 Jeep Rubicon. I cut the brake light output wire from the Jeeps brake switch, and sent it up to a two-way toggle that I installed in the door jamb of the Jeep. From one side of that toggle, I routed a wire, all the way to the dash on the coach, to an LED I installed for indication of when the jeeps brake arm was ACTUALLY BEING APPLIED by my Ready Brake actuator.

The other side of the toggle was wired right back to where I cut it in the first place. Now, when towing the Jeep, we flipped the toggle to the front which, sent that brake light signal to the dash in the coach. But, when driving the Jeep, we flipped it to the rear which, sent the brake light signal to where it's supposed to go, to the jeeps brake lights.

That system was ultra-easy to install. It just took a little time to route the wire along the coaches frame to get it to the dash, no biggie at all. It's worked like that for years now. And, as for "forgetting" to switch it back and forth, it's NEVER HAPPENED! Both the wife and I, double check both of our actions when it comes time to hookup for towing and, disconnect for driving the Jeep.
Scott

LongDogRanch · 04-09-2015, 06:15 PM

Thanks very much. Really appreciate the great comments. There's always so much info available through this website!

ShapeShifter · 04-10-2015, 08:18 AM

Quote:

Originally Posted by FIRE UP

EXACTLY!
This is why I've never been a fan of adding extra bulbs and sockets to an already crowded tail light housing.

I'm not opposed to adding extra lights, even though that's not the route I would ever use. The issue I see is when someone thinks that adding that extra light eliminates the need to be concerned about the action of the toad's own brake light. It doesn't always, as we have both discussed.

In my previous toad, there were two separate red light cavities in the tail lights, and they were isolated from each other. From the factory, the toad would flash just the upper cavity with the turn signal, and light just the lower one with the brakes. So, if signalling while the brakes on, there would be one steady bulb and one flashing bulb, but being in separate cavities with their own reflectors and lenses, there was no conflicting indications. For that toad, I used diodes to tie the MH lighting signals to the upper bulb. When turning while brkaing, the MH would flash the upper light, and the toad would light the lower steadily, just like when driving the toad normally. When braking without turning, the MH brake signal would light the upper bulb, and the toad's brake switch would light the lower - different from when driving the toad alone, but certainly not confusing.

My new toad has two bulbs in the same cavity, and both bulbs operate identically. In this case, interrupting the toad's brake signal is required to prevent the toad's brakes from overriding the MH's flashing.