Bizarre IIa tail light fault

First of all a quick hello, as I only just joined this forum whilst scouring the interwebs for a possible solution to this problem. So... Hello.

Ok, now to the problem. All the lights on my IIa were working perfectly a few days ago, but now - two days away from MOT time - it's developed a very strange fault.

Both off-side indicators now seem to be connected to the tail and brake lights. They don't work when the indicator lever is switched (near-side are working fine though). However, when the tail lights are switched on they light up permanently, and they also light up when the brake is depressed. As far as I can tell the brake lights don't light up when the brake pedal is pressed, although I can't say for sure as I don't have anyone to check for me, and they've become very dim with this fault.

I have absolutely no idea how this could have happened, as I haven't done anything with the wiring. I did knock the rear near-side tail light pretty hard whilst changing a wheel, but I don't see how that could have caused this. I've had a fairly good look at the easily accessible bits of wire and I can't see anything wrong.

Any help would be greatly appreciated as I'm no wizard with electrics and I'm completely stumped.

Earth fault. Check connections and if that doesn't help run some secondary earths to pinpoint where the problem is

oh and....:welcome2: blahdy blah blah

Go say hello in the introduce yourself section

I shall give that a go, cheers.