First of all relays and solenoids are two different things and your boot release probably has both. Where is the live feed good, you don't say? I suspect that there is indeed a solenoid that opens the boot. Have you looked for it somewhere near the boot latch? Does it move when you try to open the boot? If not, you could test it by putting a live on it to see if it moves. If it works then it will be the relay. Look at your relays and use your handbook and/or the Haynes manual to find out what the other relays do and the odd one out is the boot relay. Press the boot open buttton and listen to see if it transfers.
Finally that has teken me about ten minutes for free. I suspect that the Ford dealers aren't useless. Isn't it rather the case that you have asked them to help you for free? A technician could take half an hour or more to diagnose you problem - have you offered to pay for his time? BTW. The parts guys are often helpful if it is a common fault as they get to sell a part.
Terry (Parts Guy)
September 2006