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I have a 75 f100 Ranger 360FE, the engine starts when you turn the key but when you turn the key to the off position it won’t turn off. I replaced the starter solenoid, the ignition switch, and the ignition lock cylinder still not shutting off. What do y’all think is my problem? Someone said maybe a lose ground, does anyone know where I can get a diagram off all the grounds on the truck? Thanks everyone in advance
Well this is a change, most folks can't get it to start. With the motor running, then turn the key off. Get a volt meter and see if you still have power to the positive on the coil and the side of the solenoid that goes to the starter small terminal.
I swapped out the old alternator on my truck for a Delco 10si. Suddenly my truck wouldn't shut off. The alternator was backfeeding power into the electrical system. I ended up getting a little diode pigtail from NAPA tip fix it. So I guess what I'm saying is that if there is a diode or resistor in the voltage regulator it could be your problem.
I was watching Nick's Garage on the youtube, and he recently worked on a '70-'71 Torino GT or Cobra 429 with the same problem! The owner had rigged up a kill-button to unfire the engine...
It turned out to be the voltage regulator.
You can fast-forward through the first two and a half minutes.
Ok so I saw on YouTube that someone said you can disconnect your alternator, that the engine and if it will turn off then your getting a back feed. Well I disconnected the alternator and it wouldn’t start.
That does not sound right. What exactly did you disconnect, and what exactly do you mean by didn't start? Did it click at all? Did the starter crank the engine, but it would not fire? Or did you get nothing when you turned the key to START?
Ok so I saw on YouTube that someone said you can disconnect your alternator, that the engine and if it will turn off then your getting a back feed. Well I disconnected the alternator and it wouldn’t start.
Don't ever try that on a newer car, as it can fry today's sensitive electronics.
Don't even do it on a 30 year old car... I forget how old a car has to be for that test to be safe, but it might go back to the generator days.
It can fry an alternator too. Plenty of stories of some that have gotten away with the test once or twice, but then tried it again and lost their alternator.
Same for connecting power to an external regulator before mounting it to the body and grounding it. Some have done it and gotten away with it, while others immediately fried a brand new regulator for it.
So definitely some things to be careful with.
is it running or dieseling? pull the wire or the belt from the alternator and try it if it is running. if it is dieseling, check the tuning/timing/curb idle/blahh blahh.
Back out your idle screw some and see if if will stop then. When the idle screw is screwed-in too far, it opens the throttle plates too wide and the engine will actually pull some fuel through the main jets a little, so when you shut the engine off, the inertia of the spinning engine still pulls air (and some fuel) through the carb and into the cylinders. The heat built-up inside the combustion chambers is enough to light a few of the cylinders at random to keep the engine spinning and sputtering.
What were you doing before this started? Was the engine running ruff or something?
is it running or dieseling? pull the wire or the belt from the alternator and try it if it is running. if it is dieseling, check the tuning/timing/curb idle/blahh blahh.
This right here is a good idea. Hook your alternator back up and take the belt off instead. That should narrow it down some
Ok so I have done nothing to my truck since the last time I posted except for I pulled the battery and took it to get charged. Now I’m hen I was putting the battery back on I connected the positive and then when I put the negative on the post the engine started to crank. So I decided I would see if I could start it this way but once the engine is started I removed the negative and it dies. There is some serious wiring issue I think lol. Also it turns out someone put a alternator that doesn’t belong on this truck and deleted the voltage regulator and put a inline diode in it.
