I had a '74 4 door Maverick with a 250 automatic that would not start. There was a fuse link wire that ran from the fuse box to the starter relay. I checked it with a meter and it was open. I just disconnected it and added another fuse link wire next to it. It started and ran fine for a long time. This was back in 1981. I don't know if all year Mavericks/Comets are wired the same. In 1974 there were electronic ingition parts the older cars did not have. You may want to check with an auto electric shop. Be carefull.