Help! I have a M25 in a 1987 Catalina and I was upgrading the glow plug circuit with the recommended Coll Hersee solenoid to speed up the start up and got it all wired up and I cannot get the solenoid to switch on. I took positive from the starter post and fused that to the one side of the solenoid, cut into the glow plug line just past the glow plugs and put the short line to the other side of the solenoid and the long line(to the panel) to the small stud on the solenoid. I have power to the small stud when glow plug button is pushed and power to the large stud from starter but nothing to the large stud going to the glow plugs. What am I missing? Is there a way to see if the solenoid is bad?