Author Topic: Undumbing a starter button/ignition  (Read 1883 times)

Offline ClintoCinco

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Undumbing a starter button/ignition
« on: March 28, 2017, 04:55:02 PM »
Hey! New to the forum here and this is my first post. I've been a creeper on this site for sometime, and have found all the help I needed in other threads.

I have a 74 C10 Long bed, that I've been redoing. Got it from somebody, and they put a starter button on it. You turn the key to ignition, and push the button and it starts up. There are 2 wires going straight to the button(I'm guessing power and starter) as you can push it when the truck is on and it engages. There are FOUR wires coming through the firewall, two of them are the ones I mentioned, there is a purple one running straight to the fuse box under the IGN I believe, and then a red one just dangling.

I want to go back to the normal turn key and go instead of the button.
Now if I turn the key to ignition, you can hear the fan come on, but if I were to crank it using the regular ignition, the fan shuts off and the parking brake light comes on momentarily.

I ordered a new ignition switch, just in case the previous owner did this because it was broken.

BUT I was wondering if these 4 wires need to go somewhere else to just make the ignition work like normal again?
I'll get photos up, but I appreciate any help in the mean time!!  ;D

Offline bd

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Re: Undumbing a starter button/ignition
« Reply #1 on: March 28, 2017, 10:11:51 PM »
Inasmuch as there is no telling what has been done to modify the factory wiring, telltale pics are a must to offer any viable assistance.  In the meantime, feel free to browse the factory GM 1974 Wiring Manual and compare the diagrams to what you have.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline ClintoCinco

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Re: Undumbing a starter button/ignition
« Reply #2 on: March 29, 2017, 01:08:43 AM »
Here are the wires coming through the fire wall


The 2 that go to the button

One is very thick copper by the way

The purple that goes into the fuse box


And the dangling red


Offline bd

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Re: Undumbing a starter button/ignition
« Reply #3 on: March 29, 2017, 09:22:15 AM »
All of that was cobbled in.  Trace the four wires and discover exactly where they connect.  Draw a diagram to help keep the modifications clear in your thinking.  Refer to the factory wiring manual for comparison.  Inventory the wiring as needed to sort out everything that was done and what you will need to do to restore the factory configuration.  Likely, you're correct in supposing that the starter quit cranking altogether, or developed an intermittent cranking problem.  Instead of properly diagnosing and correcting the actual fault, a workaround patch was added. 

Since the ignition switch still seems to supply ignition power, modifications maybe restricted to the crank circuit.  Perhaps you'll be fortunate and resolve the problem with a new switch and by reconnecting original wiring that was merely laid to the side out of the way.  However, if you discover that the original purple solenoid wire is cooked from excessive heat, I recommend replacing it all the way back into the bulkhead connector using 10-gauge purple SXL wire.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)