Have now carried out a post mortem on the duff relay as suggested.
I have connected my multimeter and battery to the coil to figure out whats happening. - but I am no electrician - self taught.
Quite interesting. There are four connectors in use labelled 85, 86 and 87, 30.
85 and 86 are the 12 V supply to the relay actuating coil. 87 and 30 are the switched connectors.
Testing the circuit shows that there is a lack of continuity between both ends of the coil.
On close inspection both end connections to the coil where the very fine wire is attached to the terminal there is obvious corrosion.
Using a magnifying glass I could see that where the fine coil wire is held to the coil with some type of glue there was a break - very hard to see with the naked eye. I cleaned up the broken end and connected a 12V supply - bingo the coil activated.
My conclusion is that the wire has become corroded by moisture which has made it succeptable to breaking by ongoing vibration.
I have some very detailed photographs showing this if someone can upload then and link them to this post
Regards
Chris
