warning lights and mot

Hello, I have a 53 plate disco 2 and have the infamous 3 amigos. Various attempts have been made to get rid of them. The latest will be a shuttle valve on abs. If this does not work whats the deal with mot as any warning light should mean failure of the test. Do we just keep throwing money at it, or will they accept that brakes work fine and no one knows how to get rid of them? Thanks for any opinions.

If your doing the shuttle valves also do the wiring mod if you have any warning lights on eg safety related its an mot fail

You are at nothing unless you have the fault read. There are a lot of possible causes with this fault so throwing parts at it and guessing is a mugs game. Could be something as simple as the previously mentioned wiring mod on the modulator which costs about £5 and an hour of your time to fix. Let people know your location and there could be someone on here close by with a nanocom or hawkeye who will be glad to help.....