ok its a bosch starter made to a chrysler-ish specification.
uses a starter relay like US cars on the inner wing where they corrode in the fumes from the battery. you have one style for manual and one for auto cars only difference is the no. of connections to it Rock auto has em.
if they are old they get resistant and reduce the power to the starter
the stater is a Bosch unit. the solenoid is basically like any other. it flips the pinion out and controls power to the motor unit
if the voltage is low it doesn't engage properly and what you hear is the contacts in the solenoid cooking...... thats the Buzz
this is more likley to be
flatish battery
or
if the car has bolt on cable ends for the battery connections and a load of geen verdigris in that junction strip off clean in coke "only the real thing". put back
clean all connections battery clamp, battery clamp onto wire power to starter motor power onto stud at starter relay.
If the motor is dead a mini starter can be used but i'll need to know pinion size and tooth count before i can advise on how hard that swap will be.
my usual suggestion here is a rockauto rebuilt magnum starter with the 35 mm 10T pinion swapped for a 25 mm 9 tooth. and thats when the fun starts. no standard denso ever came out with a 25 mm 9T pinion, so its a custom job and supplies are picemeal and awkward
slant6dan has a solution
Mini Starters on a Slant Six
i emailed the suggested supplier and as per usual, they studiously ignored me.
there are alternatives, 1 is crap the other depends on the owner of the company seeing what he has in his prototype box or, usuing one that is innapropriate with an 8 mm spacer plate and the nose of the starter cut off
but as i say we won't know until you pull it and have a look...
if the car has a borg warner 35 id suggest it would have a 9 tooth 25 or 10 tooth 27mm pinion
if the car has a 904 or 727 it will probably be 35 mm ten tooth like a US mopar
if the car has been messed with well any combo of aussie and US parts makes for a puzzle
if its manual the jury is out dpends if its always been manual.
if you were in the UK i have a box full of valiant starters from the guys who just stuck in a big block and 727
electrical maladys in aussie cars seem to depend on if they lived by the sea or in semi tropical region. you will find the greenest of green all over the connectors,and the fuse box can be quite fossilised if they lived by the sea.
move them to a dry climate and the proplems pop up whenever it gets humid or rains. the green crap swells and causes bad connections.
your experience may differ but i lived this after my car was transported for 3 months in a container to the UK 3 months at sea in a sweating damp container did the electrics no good.
hours of fun with a small brush in a rotray tool contact cleaner and a small pair of pliers
if you had a wire diagram for a 1967 dodge dart you wouldn't be far off what you have provided you account for the fact that left is right and right is of course left
they didn't really do anything new.... its just a low spec dart with spade connectors where the US would have bullet connectors.
under the hood if you avoid lights and wiper/washers you are basically looking at a loom that covers tacho coil+ ballast temp sender and oil light.
on the left you have the usual rats nest by the battery which is the same as US cars
regulator starter relay alternator feed and big red wire as battery +
Dave