Strange auto electrical question

[Andy]

I have recently bought a trailer with an electro-hydraulic tipper, powered by an onboard battery. The tow vehicle has two electrical connectors, the standard one for lights etc and a second one to power a caravan.

I have been told that I can use the caravan supply to recharge the trailer battery when towing, but I cannot find any info on the connections needed.

Anyone know where I can get this info from?


Thanks

[Subafreak]

I have enough fun rewireing trailers around here, I don't even want to think of the crazy stuff over there.



Dodge Caravan

[oab_au]

Originally posted by Andy
I have recently bought a trailer with an electro-hydraulic tipper, powered by an onboard battery. The tow vehicle has two electrical connectors, the standard one for lights etc and a second one to power a caravan.

I have been told that I can use the caravan supply to recharge the trailer battery when towing, but I cannot find any info on the connections needed.

Anyone know where I can get this info from?


Thanks

Gidáy Andy, Still pedaling around the island looking for the exit.

Should not be too much of a problem. If you just connect the tow cars power to the trailers battery supply, through a diode, it will charge the battery when the cars alt is charging. The diode is to prevent the car from using the trailers supply. It would be wise to put a 5 ohm 30 watt resistor (or a light bulb of that wattage) in series with the diode to limit the current flow.

Harvey.

[b3lha]

Here you go....

http://www.electronics2000.co.uk/dat...ut/trailer.htm

Click on "Technical Data" then "Pinout" then 12N/12S connector.

[Andy]

Originally posted by b3lha
Here you go....

http://www.electronics2000.co.uk/dat...ut/trailer.htm

Click on "Technical Data" then "Pinout" then 12N/12S connector.

Thanks Phil, I had come across that site but it doesn't give details of wiring at 'the other end'

I tapped up the auto electrician at the local workshop (sneaked around the back.) He said that the official way is by fitting a split charge relay linked to the ignition warning lamp. This disconnects the 12v supply to the trailer when cranking the engine. A simple cheat is to wire in the trailer to the fridge line, which is already fed through a relay.

When charging a caravan battery, a relay is already built into the caravan, triggered by the fridge line. The caravan battery cannot be charged directly from the fridge line as it would draw too much current. I can get away with this on my trailer as I am not running anything else off the supply.

Harveys method would also be fine, but the shop is out of 25A diodes and are not expecting any in soon.