two79rx7's

greetings,

I am in the middle of rebuilding a 8 tooth bendix gear ( pinion gear ) starter for a 12a. in a 79. the 12a is an 81 or greater.

have all parts clean and adjusted.

I note in the 79 FSM and the Hayes manual that there should not be continuity between the field coil terminal and the yoke ( housing of the starter ).

This makes sense. This provides for a circuit first through the field coils then into the commutator through the armature coil; without a secondary path to bleed off energy ( a short)

But there is a small wire leading from one of the field coils and is connected right on the yoke ( housing ) with a friction fit plug holding it in place. This provides for continuity when the manuals say there should not be.

I test my field coil terminal and the yoke and have continuity.
but as above the manuals say I should not but the part in hand shows I should

the resistance is 2.4 ohms from field coil terminal and the yoke

the resistance is .3 ohms from field coil terminal to either of the 2 brushes that come off the field coil.


Anybody have a detailed explanation
is the manual wrong?
is the wire connected to the yoke not supposed to be in circuit with the field coil? but what other reason would it there for?

two79rx7's

I found out more, both manuals are completely wrong in this regard

sources which claim to be expert say the following

1. the ground to the smaller field coils is needed for keep the motor from over-reving

2. this ground keeps the starter from machine gunning on and off when placing it in demand with the ignition switch.

In my case I measured 2.4 ohms from field coil terminal to yoke ( case ) - the manual said no continuity.

I would like to see a detailed schematic of the whole system....anybody have?

short for time now
more about this later

Jeff20B

iTrader: (13)

Sorry about your problems.

I think my bro broke the magnets in the NA second gen starter I installed in his RX-4.