It will work if the pall is turned in the right direction. The mercury and ford will interchange only if the pall is in the right setting. Its seems to me the mercury needs to be turned 1/2 turn to the left. Try to install the solenoid and if it will not aliegn properly then you are going to have to turn the pall. Take the cover off and then unscrew the two little nuts, holding everthing together with one hand, back off the cover holding the pall about 1 inch and then take the other hand and rotate the pall 1/2 turn (I believe to the left), bolt the nuts back up and try to install.. Hope this helps. Regard, Charles