Bentley Arnage Project - Weird Electrical Problem Fixed

I thought this one was worth a quick few lines as it had me perplexed for a while and is perhaps a useful lesson that sometimes things that seem difficult are quite simply explained and fixed.

So I was working on that bloody speedo again, thought it was fixed but it clearly isn't. I had taken the dash back off and had removed the clear plastic cover that goes over the speedo so I could wiggle the gubbins while driving to see if I could work out if there was a bad connection. I noticed that every time I put my foot on the brake the panel lights came on and the warning light for lights on also lit. I also noticed that the leds in the a/c control panel went off. On further inspection they had just dimmed. I tested the light switch, that was doing the right things but it was only when I went and got Mrs to check to see what my exterior lights were doing that the fault became a bit more obvious.

I got her to switch the lights on and saw that the high level rear brake light came on. I then got her to turn the lights off, turn on the ignition and hit the brake pedal - the brake lights all came on but so did the side lights. I know that because I had taken both rear light units out and let them hang loose - sometimes it's hard to see if the side lights are lit when the brakes are pressed. It was in doing this that I spotted the problem. Somebody had put a brake / stop light bulb in incorrectly and had somehow managed to short the brake and side light contacts. I took it out, put it in correctly, tested everything and now it's all good except my fecking speedo still doesn't work LOL. Also in doing this exercise I realise my brake spheres are shot, I only get about a dozen pumps of the pedal with the engine off before the pedal goes hard. Bugger and hairy bollocks!! 

I thought for a moment that maybe I had an earth problem but now I'm back to looking at maybe a knackered stepper motor in the speedo. I cleaned all the connectors in that back - no difference. Next job is to try cleaning and reseating the ribbon cables, I have a temporary fix of a GPS driven LED unit, tenner off ebay, probably not the most reliable or beautiful device but it will help keep my licence clean. If I can't get it working at all I will adapt an analogue gps unit to go in the dash and use the original dial, that will look a lot better and will be a much neater solution.