Wiring tow lights

[gumpy]

Nick
  As of now, I finished mounting an extra light on each of the magnetic lights and ran a separate wire for it to be the brake lights.  It bench-tested fine, but went weird when attached to the bus.  Since I am using the four pin connector that was there when I bought the bus, I will now have to take a closer look at it to determine if it has problems.  Otherwise, it is possible that there is some bleeding back through the bus system and I may need some diodes.   I am not an expert at this, among many other things, so my solution may not be particularly graceful, but right now I just want to get to our new home with all (reasonably) intact. 

     Thanks for the diagram.  It looks like a clearly superior way to go.  I will probably stick with inferior now.  There is just to much to do before we leave.

It never ceases to amaze me how so many will come to this board asking for advice, and then simply ignore it when provided.

Wiring 12v 3-circuit toads on a 24v 4-circuit bus is not a new problem you've discovered. Many of us have been dealing with it for years. In this thread and through the links to the other thread, there are no less than three different schematics provided which give perfect solutions to this common problem and which are all tried and true. They all provide nearly identical results, with the primary differences being cost and ease of installation. I understand not wanting to spend the money to purchase a pre-built converter unit, or buy the components to wire one up with the expensive octal relays like your bus uses, but both Jack and Sean have given schematics which use inexpensive cube relays that can be purchased for around $3 each, or even less.

In the time you've spent bantering this around on the bulletin board and trying to jurry-rig your existing connector and magnetic lights with extra bulbs and all the other BS, you could have scrounged or purchased all the parts and completed the installation of one of these other systems which would make your bus tow ready for any and all 12 volt toads and you'd never have to mess with it again. Probably would have saved money, too. Yet after all this, you've decided to continue trying to make your existing hodge-podge system work. And you still don't have tail lights.

And what's worse, every time you want to tow something else, you'll have to start this whole mess all over again.

I just don't get it.

Anyway, good luck with it. If by chance you do happen to be the one to finally solve this never ending toad wiring problem, please post your results here so the rest of us can benefit from your breakthrough.

[gumpy]

Hi Sean,
In studing your relay diagram it appears that the turn signals on the towed vehicle will flash twice as fast as the towing vehicle if the brake lights are on at the same time as the turn signals. It appears that the turn signal relay becomes a flasher too when the turn signal flasher alternately switchs the turn signal relay off and on, thus causing the brake light to also switch off and on. Or, am I overlooking something.
Thanks, Sam 4106

Sam,

Notice that power to the turn signal relays comes through the brake relay. What happens is when the brakes are applied, the brake relay switches power out through the two blinker relay NC contacts to the lights. Then, when a blinker is turned on, it causes the blinker to switch between the NC contact to the NO contact and back. Notice that with the brake on, there is no longer any incoming power on the NO contact, so when the turn signal switches to the NO contact, it breaks the circuit to the light. The result is that while it blinks at the same rate as the bus, it blinks out of sync. In other words, when the brakes are on, when the bus turn signal is lit, the toad turn / brake signal is not lit, and vice-versa. When the brakes are off, though, the turn signals are in sync.

craig

[Lin]

Grumpy!

     I understand your complaint about not listening to good advice, but we are under some time constraints here.  I posted in the AM looking for a solution, but I had to get this done and out of the way.  The converter would be fine, but the stores I spoke to would not commit to it not frying on 24v.  Changing the bulbs in the tow lights was quick and easy as was adding a separate light to the fixtures.  Yes, it is also cheap.  That it is not working correctly points to some issue with the wiring in the bus which probably would have showed up not matter what I did.  I am sure you have started out at some time with what seemed like a reasonable plan that did not unfold as you had thought.  In short, give me a break!  Anyway, I like my newly adapted tow lights.  I think they have character.

[Sam 4106]

Hi Gumpy,
Thanks for your explanation. I was overlooking something.
Sam 4106

[Sean]

...
In studing your relay diagram it appears that the turn signals on the towed vehicle will flash twice as fast as the towing vehicle if the brake lights are on at the same time as the turn signals. It appears that the turn signal relay becomes a flasher too when the turn signal flasher alternately switchs the turn signal relay off and on, thus causing the brake light to also switch off and on.

Sam,

I think you must be misunderstanding the diagram.

The turn signals on the trailer will flash at exactly the same rate as the ones on the bus.

This diagram assumes that your trailer has combined stop/turn lamps.  That means that there is no separate brake lamp -- it's the exact same lamp as the turn signal.

When the brakes are off, using a turn signal will cause the lamp on that side to flash on and off at the same rate and time as the bus turn signal.

When the brakes are on (with no turn signals), the lamps on both sides will be on.

When the brakes are on, and you also activate a turn signal, the lamp on the turn side will flash, while the one on the other side will remain steady.  However, the flashing turn lamp will now be "on" when the bus turn lamp is "off", and vice-versa.  In other words, it will flash at the same rate, but out of step with the one on the bus.  This is normal.

HTH,

-Sean
http://ourodyssey.blogspot.com

[Sean]

Sorry for the duplicate answer...

I didn't notice there was a second page to the thread when I typed my reply to Sam.

-Sean
http://ourodyssey.blogspot.com

[gumpy]

Grumpy!

     I understand your complaint about not listening to good advice, but we are under some time constraints here.  I posted in the AM looking for a solution, but I had to get this done and out of the way.  The converter would be fine, but the stores I spoke to would not commit to it not frying on 24v.  Changing the bulbs in the tow lights was quick and easy as was adding a separate light to the fixtures.  Yes, it is also cheap.  That it is not working correctly points to some issue with the wiring in the bus which probably would have showed up not matter what I did.  I am sure you have started out at some time with what seemed like a reasonable plan that did not unfold as you had thought.  In short, give me a break!  Anyway, I like my newly adapted tow lights.  I think they have character.

My appologies if that came off too critical. Just seemed like you were fighting a number of problems on the bus wiring, and taking a couple hours to put in a relay system might have saved considerable time and effort.  I realize that's hard to do when under the gun, sometimes.

Yes , once I started out with a reasonable plan that didn't unfold as I had thought. I like to call it my bus conversion project 

Thanks for the email. It was right on the mark.

good luck with your bus, and with the move.

craig