I have a 1978 MF 255 Diesel.
After replacing the fuel filter, I was air bleeding the fuel system.
During this, the motor stopped cranking. I started checking, and could not see any voltage on the hot wire from the key. It’s a pretty simple circuit. Hot wire comes from the battery to the solenoidn. Hot lead goes the starter to the key switch. From key switch, it goes to the safety switch. And from there, it goes to the hot lead on the solenoid. When I turned the key on I get 12 1/2 volts on the hot lead of solenoid. Also on the lead coming from the solenoid to the starter itself, voltage hits about 10 1/2 V. This would be the cranking lead to the starter. The problem is I get nothing. The solenoid does not engage the Bendix to lock the starter to the flywheel and the starter does not spin. This is a new solenoid that I bought from the local Agco dealer. I can feel the solenoid quietly humming when the key switch is on, but there is no audible click like the Bendix has moved. with the solenoid off, I can move the Bendix drive back-and-forth to engage the flywheel manually.
Any help with this would be greatly appreciated. I’m at my wits end right now.
Chris
After replacing the fuel filter, I was air bleeding the fuel system.
During this, the motor stopped cranking. I started checking, and could not see any voltage on the hot wire from the key. It’s a pretty simple circuit. Hot wire comes from the battery to the solenoidn. Hot lead goes the starter to the key switch. From key switch, it goes to the safety switch. And from there, it goes to the hot lead on the solenoid. When I turned the key on I get 12 1/2 volts on the hot lead of solenoid. Also on the lead coming from the solenoid to the starter itself, voltage hits about 10 1/2 V. This would be the cranking lead to the starter. The problem is I get nothing. The solenoid does not engage the Bendix to lock the starter to the flywheel and the starter does not spin. This is a new solenoid that I bought from the local Agco dealer. I can feel the solenoid quietly humming when the key switch is on, but there is no audible click like the Bendix has moved. with the solenoid off, I can move the Bendix drive back-and-forth to engage the flywheel manually.
Any help with this would be greatly appreciated. I’m at my wits end right now.
Chris
