towing connection wiring question

[Kenty]

Calling all auto electricians!
I want to tow my caravan (12v) with both my car (12v) and truck (24v).
Converting the caravan to 24v is obviously not the answer, does anyone do this?
What is the best way to go about it?
I have seen a voltage converter on ebay for a 7 pin plug at £132, yikes! Is
there another way?

[Jetblackonetenth]

what about putting LED bulbs in all the caravan lights as these sometimes can work at 12V and 24V.

[C0ffin D0dger]

Jetblackonetenth said:

what about putting LED bulbs in all the caravan lights as these sometimes can work at 12V and 24V.

Not quite as simple as that. The incoming supply from the vehicle does more than just run the indicators, it charges the 12V leisure battery so 24V not good here, and runs the fridge also 12V though you could turn that off. Not going to be straight forward unfortunately.

[Jetblackonetenth]

C0ffin D0dger said:

Not quite as simple as that. The incoming supply from the vehicle does more than just run the indicators, it charges the 12V leisure battery so 24V not good here, and runs the fridge also 12V though you could turn that off. Not going to be straight forward unfortunately.

I did think of that, but as he mentioned a 7 pin socket I thought he may be on the old fashion one where the lighting is on a separate socket.

[Kenty]

Thanks for the replies guys.
My 7 pin doesn't charge battery or fridge but i have a lot of lights on the van
i would need to change, amber lights along the sides as well as all the rears.
Out of interest would LED's work on both voltages?

[shovelheadrob]

Not all LEDs work on 12/24v, many do though.

[gareth_r]

Could you not use a 24V to 12V DC converter on the truck, then switch the resulting 12V supply with 24V relays?

EDIT:
Actually, it appears that you can just buy a 24V to 12V bypass relay.

https://www.ebay.co.uk/sch/i.html?_from=R40&_s...

It's a while (i.e. decades) since I wired up a towbar, and back then I had to do it all myself.

Edited by gareth_r on Thursday 21st February 19:19

[Kenty]

gareth_r said:

Could you not use a 24V to 12V DC converter on the truck, then switch the resulting 12V supply with 24V relays?

EDIT:
Actually, it appears that you can just buy a 24V to 12V bypass relay.

https://www.ebay.co.uk/sch/i.html?_from=R40&_s...

It's a while (i.e. decades) since I wired up a towbar, and back then I had to do it all myself.

Edited by gareth_r on Thursday 21st February 19:19

That looks like the one I need, only £32, looks like it will need to go in a waterproof box. Thanks Gareth!

[Dog Star]

We used to have a 24V Landcruiser - we dropped the voltage going into the towing electrics using a Durite 12V regulator thing (actually we added a second so that we could do fridge etc).

This was my solution to the problem, this was distinctly better than the dealer solution of simply taking the +ve feed off one of the batteries (the first in series). That didn't end well.

Long time ago now - that car went in 1996.