MG Car Repair: tail light wiring, mgb roadster, wiring loom

Question
Hi Bernie,
 I purchased a LED tail/stop/turn lite kit. I can not get the wiring correct. Original wires to turn signal was green. only 1 wire. Stop/tail lites had red & green/red wire.
 New lites have yellow & green for turn signal and red,black & green for stop/tail lites. I know both green wires are ground
and I connected them to housing. I got tail lights. No brake lites or turn signals. Instructions said connect black wire to tail lite feed (HOT?). Which is feed? Hope you can help.

   Thanks,
    T.V.
P.S. My car is a 1979 MGB roadster.

Answer
Hi T.V.  The original Lucas rear lights had a plain green wire to the turn indicator, red wire to the sidelight, and green with a purple stripe to the brake light.  

The wiring loom had plain red for the sidelights and red/purple for the brake lights.  The turn indicators were either green/white or green/red depending on which side of the car you are working on.

Unfortunately, I cannot confirm the wiring colours used on an aftermarket LED lighting kit.  However, you must remember that LEDS only work one way round.  If you wire them the wrong way round they don't get damaged, they just refuse to light up.  Try reversing the wires to the lamps that do not work.

By the way, the turn signals require a load of 48 Watts in order to flash at the correct speed.  You are replacing the rear bulb (21W) with a LED that takes almost nothing.  Therefore, you may find that the flashers operate too fast.