I have a project car with a 1975 360 motor and transmission. I got part of the original wiring harness and starter solenoid. It is a rectangular metal box with four posts. My battery is in the trunk so I have run the hot cable to the big battery post on the solenoid. There are three connectors and a bit of wire from the original harness attached to each. There is one with a smaller diameter green wire, and orange wire. The fourth is a heavy (about 10 gauge) red wire attached.
I am guessing from the wiring diagrams I have found that the green goes to the neutral safety switch and the Orange to the ignition switch start run position? I am guessing that a shorter hot cable needs to be attached at the battery in and run to the starter motor? I don't know where the other post with the 10 gauge wire should go?
The starter came with the double connector and a bit of the battery cable and a smaller brown wire attached to the small post on the starter. I don't know where it should go also?
I will really appreciate help in getting this part of the motor wired correctly. Thanks

I think that 10 gauge should be the fusible link that feeds the main power to the amp gauge and from the gauge goes to the ingnition switch etc. It goes through the bulkhead connector. Brown wire goes from the start terminal on the starter relay to the starter selnoid S post.

BTW the square box is a starter relay NOT solenoid. The solenoid is built intregal with the starter.

Thanks. The face of the relay is aged and I can't make out any marking next to the posts except for the Battery terminal. So I have the ten gauge which makes sense goes to the alt and on to the ignition switch. That leaves two more connectors on the relay. Green and orange wire. Any guess on which one would be the correct one for start?

New relays are about $16 at most parts stores.

With the spade terminals at the top the green wire goes to the top left the orange wire goes to the top right. The battery and large starter wires plus the wire to the inside of the car to the ignition go on the big round terminal and the brown wire goes to the terminal with the screw.

if you ever run across a factory service manual GRAB IT,thier worth thier weight in gold.i see them on Ebay from time to time.

Thanks for all the suggestions. I took the advice to get a new relay. That second post with the red wire should be to the solenoid. The two remaining are slip on posts and are marked G and I. Part of the problem I am facing is the motor and trans is Dodge, the chassis is a S10 and the body is a 1941 Willys three window coupe. I an using a universal 20 circuit wiring kit. Thanks everyone for your help.