Alright lads, basically my lights have went bonkers on my sierra. Front Lights work 100% But back lights have recently decided to go haywire, in reverse a brake light and reverse light comes on, when braking a reverse light and brake light comes on, and when reversing and braking at the same time my right indicator comes on aswell? Thought it was bad earth so tryed to fix it today but fucked them up even more, a mate reckons its the back light circuit board unit and too borrow a set to try see if thats the problem.

Anyone have any expierence with this happening? Is it common or is mine just fucked? Any advice appreciated, cheeRS

 

it is a bad earth and 9 times out the 10 another pair of lamps should do the trick!

ps you could try to clean the plugs on the lamps 1st!

 

it'll be the earth(s) from the lights - get some sand paper on the rear light contacts, and make sure the connector terminals (on the wiring loom) are nice and tight

 

cheers lads, already done earths and cleaned plugs so will get new lamps now too see if it will work. If not she will just have to go to an auto electrics

 

Try running a seperate earth as a test to a GOOD earth point, the earth is likely to be corroded and so even cleaning will do no good..

Martin

 

Just hard solder the wires to the light board tracks, ford used galvanised steel for the light tracks, which is bad news for conductivity lecky wise, the micro arcing that occurs on the pins then burns off the galvanise letting the pins/connectors rust.
Even when sorted always run a seperate earth, to a decent point, takes all the trouble away.
I drill a 3mm hole in earth track then insert a tinned wire and solder on, it will not come off ever if done correctly then other end put a terminal etc as needed and earth down.
You can use the same technique to join the loom to the light board tracks, could also do the brake/fog light mod whilst there so fogs come on with brake lights, via some rectifier diodes, all easy to do cost around 20-30 pence, 100% LEGAL and MOT passable, do this on all my cars, have done for 20+ years, makes a huge amount of difference having fogs light up with brakes, but still work on their own as fogs without affecting brake lights.
tabetha