Author Topic: 1975 C6000 GMC  (Read 973 times)

Offline CedarRidgeSawmill

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1975 C6000 GMC
« on: January 05, 2021, 05:45:55 PM »
Hello, really stumped here. I picked up this flat bed/dump for around the farm work. Its actually a really cool truck. It starts, runs good but won't shut off. I have replaced the the ignition, it has a new battery and alternator. Can not guarantee that there was not some red neck wiring prior to me owning it. Any suggestions on where to start on this, tired of popping the clutch to kill it. :)

Online bd

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Re: 1975 C6000 GMC
« Reply #1 on: January 05, 2021, 09:28:09 PM »
Gas or diesel engine?  I assume it has dash gauges.  Will the engine shut off if you unplug the two-wire connector from the alternator?
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 CedarRidgeSawmill

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Re: 1975 C6000 GMC
« Reply #2 on: January 05, 2021, 10:55:43 PM »
350 V8 Gas. I did swap the two wires on the alternator not knowing if they were in the right spot but I haven't tried disconnecting to shut it off. If it does shut off what would that mean?

Online bd

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Re: 1975 C6000 GMC
« Reply #3 on: January 06, 2021, 12:07:58 AM »
It would indicate that the regulator circuit has been altered with the "surprise" side effect of feeding power directly to the ignition system, bypassing the switch.  Thankfully, not difficult to correct if that is the case.  Regardless, you'll need to verify that the regulator wires are properly connected to the alternator.
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)