1973 Topkick Wiring Help Please...

[Tokin]

Hey folks! I sure someone can help I hope. I am working on a 1973 GMC 6000 Topkick with a 327sb motor. The owner "replaced" some wires from the wiring block on the firewall to some of the ignition and starting components. My problem is that I dont trust his wiring replacement was correct as the truck wont turn over. He also replaced the ignition switch in the cab but i have no way to tell if he did any of this right. Im looking for wiring diagrams for this truck but have so far been unable to locate any such animal on the web or anywhere else. I live in a remote section of Northeastern Washington and dont have internet or even electricity so I rely on the public signal when im in town. Any help with this would be great as this is a wood hauling truck and is very much needed. Thank You very much in advance.

[HawkScot]

1973 was before all the computer stuff so it should be straightforward to determine what's up. I wrote a long explanation and then erased it since your best bet may be to go the public library and see if they have a "Motors" manual for that truck so that you can make some copies of the wiring diagrams. Good luck!

[Tokin]

1973 was before all the computer stuff so it should be straightforward to determine what's up. I wrote a long explanation and then erased it since your best bet may be to go the public library and see if they have a "Motors" manual for that truck so that you can make some copies of the wiring diagrams. Good luck!

 

Well thats part of the problem. I have been unable to locate any manual with the info I need at the library. Thats where I am now and thats why I have turned to you fine folks in hopes that someone might have a manual that I dont have access to and could post or email the diagrams. I have spent the last 2 months looking for this info elsewhere with little luck and dont have the cash to purchase a manual as most of us out here are struggling for food and wood for heat. I do thank you for your help and your time.

[HawkScot]

Sorry, I was hoping you had not thought of that yet and it would solve your problem....

[HawkScot]

I will double check my old Motors manuals to see of any of them cover your truck.

[skills4lou]

Hope you got this working, but if not here's a basic idea of what you need from the dash/firewall:

 

1. Switched 12v+ to one of the connections in the HEI distributor cap. I can't remember which of the three terminals it is, but if you yank the top of the cap so you can see the coil you may be able to figure it out. This is the one that energizes the coil, and the engine will run as long as power is applied

 

2. Momentary switch 12v+ to the small terminal on the starter solenoid. This is what engages the starter motor.

 

That's all that should be required on your truck. There'll be others too, but that should get the engine turned over and fired up. If the ignition switch is too much of a pain to trouble shoot, you can always buy a universal one and wire it up yourself, bypassing all the f-ed up wiring.

Good luck.

[Tokin]

Hey thanks guys. I really need to have a diagram to follow all the wires from the firewall if possible or a hand drawing, anything that i can reference while in working on this. I do thank you all for your help in this.

[Tokin]

Hey thanks guys. I really need to have a diagram to follow all the wires from the firewall if possible or a hand drawing, anything that i can reference while in working on this. I do thank you all for your help in this.