77 ford 351m motor won't start?

77 ford f 250 with a 351m engine, Problem, will not start, very weak spark, took voltage reading at coil only have 7 volts dc, traced it back to ignition control module the 2 wire (red/green, blue) has 12v dc, but 4 wire coming out to coil and distributor only 7 vdc coming out of module, changed module twice still not 12v

Remove ford parts install chevy parts, problem solved

Try checking all your connections to make sure the copper in the cords hasent gone bad

Have the battery checked to make sure its good. If it is, the next thing to check are the battery cables, in particular the ground cables. Make sure you have a good ground directly to the engine block. Also make sure the cab and frame have good grounds also, this doesn't have anything to do with the starting problem but it will help avoid other pesky electrical problems down the road.
Clean and tighten all of the cable connections.
If there's still a problem, have the starter checked.