HELP - Rewiring 7 pin socket on JD 2040S

hward · Nov 2, 2016

I've got a John Deere 2040S and I managed to completely bust the part where I plug the 7 pin socket in for trailer lights. I completely smashed it so I can't tell which wires go into which pins on the new one. The problem is it's the old 5 wire system to go into the 7 pin socket and the wires are totally different colours to what they are now. Does anyone know which are which?

The colours I have are - black/green, black/white, grey/black, grey/red, black/red

I'm fairly sure that the black/green wire in the right hand indicator as it was still attached to a piece of the old plastic when I unscrewed it, but I've not a clue about the others.

bigtiller · Nov 2, 2016

If you can't find out on here........ Back up to the trailer and ground it to the tractor. With a long jumper wire, start poking around until the desired bulb lights up. Wright it down on paper and keep going until all the pins have been identified.

TractorTech · Nov 2, 2016

What I could find was that the black/green is RH, black/white is LH. The other colors I haven't found anything conclusive, but gray/red should be +, gray/black - and black/red stop, if you haven't already deduced.

hward · Nov 4, 2016

Thank you both, I managed to fix it today. In addition to the indicators - black/red was earth, and grey/red and black/grey were the tail lights. And it seems that there isn't a wire from the tractor for stop which seems odd, but the brake lights have never worked on the tractor or the trailer lighting board since I got it.