12 VDC light controller source?

[Catigale]

My lights on my Tow Vehicle have gone out, and I have traced it to a grey box with no marking on it. This box is a logic board which takes the signals from the tail, brake, and turn signals and powers the trailer lights from its own 12 VDC feed.

The dealer has no idea where to get it. Ive searched Champion, Trailer Parts supply, and E-trailer sites - no joy.

Any ideas??

[rwmiller56]

Is this grey box on the tow vehicle or the trailer?

[nedmiller]

What Brand of Tow Vehicle?

My F150 has an odd separate fuse box under the hood on driver's side with fuses for the trailer lights.

SILK

[Catigale]

The grey box on the Tow Vehicle...I have seen them on the web but know not where....

[Sumner]

If your tow vehicle has separate bulbs for the stop and the turn signals a box like that is needed and they are available from about any auto parts store and aren't that expensive,

Sum

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[kmclemore]

It's not one of these is it?

http://store.uhaul.com/Wiring__lights/M ... ed_Vehicle

http://www.amazon.com/VALLEY-32250-Trai ... 15&sr=8-16

http://www.amazon.com/TAIL-LAMP-CONVERT ... 215&sr=8-2

http://www.amazon.com/Reese-Towpower-74 ... 215&sr=8-1

[Catigale]

Advance Auto in town didnt have them

KMC - thanks, Hopkins was the name I saw before - now I just have to figure out which one I can plumb into the Eurovan...thanks..

[opie]

sorry, see C's comment below. This won't work if you are braking and signalling at the same time.

[opie]

Here is a drawing of what I did.... [not]

Sorry, won't work. See C's comments below.

[Catigale]

Thanks Opie

The box I have has one additional feature of powering the trailer lights from its own 12V source instead of the lights themselves. I like that feature. Im not sure I like it 40 USD worth though.

[opie]

C,
OK, we'll just add 4 silicon controlled rectifiers to the circuit and have them triggered by the truck wires and then the scrs will take their own 12v source to the above circuit. $1 a piece for the SCR's but now we are up to two hours of soldering and at your hourly rate of $95 it would be cheaper to buy....


Seriously, it would not be hard to do, but is it worth your time involved to make it? I'll draw up a circuit diagram if you think, "yes."

[Sumner]

http://www.amazon.com/gp/product/B0008G ... 2F562HRH1Z

[Catigale]

Thanks again Opie - yeah, once my rate comes in the 1/2 hour becomes important compared to pointing and clicking on the internet. The last step I have to do on any circuits is look it up in Horowitz and Hill to see if its a 'light bulb circuit' or a 'bad circuit idea'

PS - you do need diodes in both the tail lights, so that the 12V from the brakes doesnt go back to the turn signal circuit. There is one more problem, when you brake and indicate, you want the brake circuit to be passivated on the side where you are indicating (so you have one steady brake light and one indicating light. That circuit is crying out for a little bit of TTL logic of course.

[opie]

C,

That is the reason I like this forum b/c you learn alot. As some of you know, I use a Jeep to pull the boat and trailer with factory tow package and tow light cable. But I use a Ford Ranger to pull only the trailer when that is needed. So for two years I have driven the Ranger (infrequently however) with an incorrect lighting wire package I made myself with diodes that did not work in the instance Catigale mentioned so politely, when braking my signal lights did not work. How dumb, but that is what you guys do, keep us all on our toes.
So, on to Autozone or wherever to buy the right light module for the tow lights for the Ranger.
Thanks.

[Catigale]

Opie - I think you can make up something which addresses these issues with passive components without reverting to TTL - let me think about it and see if I can sketch it out - basically all you need to do is switch off the 12 VDC from the brake wire when there is 12 VDC on the turn signal wire - pretty easy to do with some power Qs.

( I think you can buy this circuit for about 20 USD though..)