On my 6.3544s, the solenoids are an integral part of the starters.
There is a small lug on the side of the solenoid where the solenoid's magnetic actuators get power
from the start buttons. The wire from the starter button goes to the lock-out switch on the transmissions, which ensure the engines are not started in gear
. A red striped-yellow wire goes from the lock-out switch to the small lug on side of the solenoid that activates the solenoids.
By the way, I think these switches are good. If the shift lever is not in the proper position, no power
will go to the solenoid actuation lug and the actuator will not move. I can hear the actuator move, so the lock-out switches must be good and I must have the shift lever in the correct position.
Question??? Is it possible these lock-out switches could be "worn" such that pushing the start button 3-4 times builds up enough heat in the switch that they let the power through to the solenoid? I could try bypassing these lock-out switches if I determine the problem is in the start button circuitry.
When I push the start button the solenoids magnetic actuator accomplishes two tasks. 1) it moves the bendix gear
such that it meshes with the gears on the fly wheel
. 2) It engages internal contacts that connect the power from the solenoid's battery terminal to a large metal strap, also connected to the end of the solenoid, that goes through the starter housing and provides power to the starter motor
, causing it to turn.
By shorting between the solenoid's battery connector to the large strap going into the starter motor
, I am only bypassing the solenoid's internal contacts that connect the battery to the starter motor, thus, I only get a spinning motor, without the bendix gear engaged, because the magnetic solenoid is not actuated.
I have done this test and the starter turns enthusiastically, without actuating the magnet and engaging the bendix gear.
By shorting from the battery power post to the smaller solenoid lug where the wire from the starter/transmission lock-out is connected, I bypass the starter button and transmission
lock-out. In this case the bendix should be engaged and the solenoid should "make" the connection from the solenoid's battery terminal to the strap powering the starter. The engine should turn.
I have not done this!
It is very hard to short from the battery input post to the solenoid "actuation" lug because of a housing barrier designed into the starter to ensure such a short never happens by accident
After I clean a couple of remaining starter button connections, and try one more time using the starter buttons, I will build a jumper cable to accomplish the "button bypass" application of power to the solenoid actuation lug.
If the engines start every time when I bypass the starter button circuits, I will know the problem is in the wiring and/or the buttons, not the starter.
If the response is the same, I suppose its time to rebuild
Please let me know if I got the process wrong. It is more than possible
And, thanks for all of your help.