it sounds very much like you have an earthing problem best bet is to invest in a curcuit tester,firstly test all the wires in the truck side socket first, the thicker of the pins in the plug will be the earth, put the tester on the earth pin with all electrics off test all the other pins 1 by 1 none should be live,now switch side lights on and you should have 2 wires showing up as live,if so switch indicators on do left side first then right sideif they are ok with side lights still on try the hazards if they are ok move on to brake lightsif all ok move on to trailer socket, taking note of colours match the pluggs together and test the trailer using the same method, good look
jimbob, November 2008
