Blazer starter installation question

[Desert Rat]

The PO installed some kind of aftermarket starter which I am replacing. Picked up a stock style starter but am having trouble figuring out the wiring. I have a shop manual for the 74 Blazer but for some reason the wiring diagram is only for a six cylinder. I have a 76 Blazer wiring diagram but it has some differences it seems. Here is what I have:

Two thick red wires that join into one that come from the junction block and somwhere else
One black thick wire comes from ?
One brown wire that comes from the firewall wiring block
One yellow wire that runs back to the HEI distributor
The battery cable that comes from the battery.

Obviously the battery cable hooks up to the large copper post. There are two other small posts, one labeled with an S and one labeled with an R. Where does everything go? /forums/images/graemlins/dunno.gif Clearly I am a complete simpleton when it comes to electrical.

 

[diesel4me]

The starter will have 5 wires total going to it if it had points--four if it has HEI--the 2 big red wires with the fuseible links go on the large copper stud on the solenoid first--the positive battery cable goes on top of them on the same stud(3/8 thread)--there should be a purple wire,that goes to the "S" terminal on the solenoid(that makes it crank when you turn the key)--if it had points the yellow wire goes to the "R" terminal on the solenoid--not used with HEI.Your wires might not be original,going by the colors you listed--the diagram for the 76 should be the same as the 74,and sixes and V8's have the same or nearly the same harness and color code.Dont know what the brown wire was for--might have been added on for a power source for some accessory by a previous owner--the black one may be the purple wire in disguise--if it gets power only when you turn the key to start(check with a test light)its the purple wire for the "S" terminal.Happy wiring! /forums/images/graemlins/crazy.gif

 

[Desert Rat]

Thanks for the help. There is definitely a wire coming from the HEI, it is yellow. However, this is an MSD pro-billet distributor. Should that hook up to one of the small posts on the starter? In the wiring diagram, the purple/black wire goes all the way back to the firewall wiring block I think. But, it seems that the brown wire does as well. I guess I'll have to open up the bunch and see more clearly where it goes. Thanks for the help. Anybody else have any suggestions on those yellow and tan wires?