Thread: 300tdi cigarette lighter problems

You've gone and fitted the lamp's power wire to the earth lug on the fag lighter socket. Run an independent earth wire if you can't work it out.

what you've done is put the light wire on the earth of the socket.

when the lights are off your getting your earth connection through the dash and park lights.

when you turn the lights on the wire is at 12v+ and the tip is at 12v+ so theres no change in potential and the electrons just hang around twiddling their thumbs.


heres how to sort it.

grab a test light or a multi meter.

put it onto one of the wires and connect the other end to a good earth point.

turn on the ignition, if the wire goes +ve or the light lights thats the center +ve feed for the socket (sounds like youve got that right anyway)
grab another wire, turn off the ignition and turn on the lights. when you get the same thing thats the wire that turns on the light. tape it up if you dont need it, I usually tap this wire for gauge lights.
grab the last wire.

put the earth from the meter on that wire, then test from the center positvie with the ignition on, you should get a light or +12v reading. turn on the lights and it should stay.

repeat the test with the light wire,

plug it all up and test it in position using only the body of the cig socket.

its also worth testing from the body of the socket to an earth point with the igntion on and off and with the lights on and off to make sure you dont have any shorts that are internal to the socket or light assembly