Dirty battery terminals can help that to happen.
for what its worth my money is on the ignition switch be sure to let us know
I backed into my spot but wasn’t satisfied with the angle. Moved forward, put it back in reverse and at this point I turned on the lights while I was moving in reverse. The engine had an electric shutdown and stopped.
more info on that battery -> the other battery was smaller and it was loose inside the battery compartment. But since there have been almost a year I don’t remember the exact spec differences between the ford battery I have now and the other one.
Is the new battery secured? Is it possible the battery shifted while you were moving and caused a momentary short?
As other have stated already, the problem is in the wiring between the battery and the power buss to the accessories of the car. Not the charging system. The voltage you stated is just fine for charging the battery.
This trouble could be difficult to find since it is intermittent. One thing that may help locate the trouble is to tap on suspected connections and items that provide power to the areas that were noticed not to working when the trouble occurred. I like to use a screwdriver handle to tap with.
Never quite thought about it. That makes sense since there was a drainage a few inches dip that was on my path. I felt a unfamiliar bump because I typically drive over that drainage moving forward. This time I was reversing. It is worth checking it out. Thanks.
OP: Someone at another forum suggested tapping the fuse box with the back of a screwdriver.
The tapping trick works very well in finding loose connection problems and others that occur with vibrations. Sometimes all you need is a light tap in the trouble area to find the problem. This trick has led me to a lot of trouble spots in things I have worked on.
I think you need to trace the path from the always-on 12V line of the radio back to the battery. Check every connector for corrosion, including fuse holders. If that path includes the ignition switch that would be my first suspect.
Yeah, the radio losing it’s presets argues against the ignition switch being the problem, but I would not totally rule it out. The preset thing, to me, argues for it being a bad battery or ground connection most likely in the engine compartment, but possibly under the dash or near the fuse block.
This kind of problem is not the alternator or battery, its a connection or fuse. Because it is intermittent and kind of rare at this time, you probably are not going to find it. If you have a large fuse near the battery terminal, I would pull it and clean the blades as a precaution, but I can’t guarantee that it will help any.
The problem has to be in that area though and it would be a connector that doesn’t take changes in current flow very well. The sudden demand of the headlights probably dropped voltage across this connection to just below the threshold need to sustain the memory and the ignition.
Just had another thought, if the + battery terminal has one or more smaller wires attached to it via a nut or wingnut on a stud, remove and clean these connections.
Keith I agree with your comment about the likelihood of finding it… unless it was loose battery that shorted (you’ll easily find black “arcing” marks).
But I disagree with your comment about a bad connector “that doesn’t take changes in current flow very well”. A connection that has resistance will indeed drop the volyage when you draw a current - and that could cause engine cut-off. But the condition is not caused by “sudden change in current flow” rather it is “high current flow” (sudden or otherwise) that causes this (voltage drop is current multiplied by resistance). If you are suggesting that the surge from turning on the headlight caused the connection to fail at that moment - that is possible, but it likely wouldn’t go back to normal after you cut off the current. The car starting right away and everything being fine is not consistent with that failure mode.
maybe a new fuse chip would be the solution. in some occasions thats possible that the belt malfunctions.
This is the most on point post. If the radio is a factory install the always 12v failure is the correct path. But don’t forget the grounds. An intermittent ground will cause a power source fail as often as not. If you lose ground it does not matter if you have volts on the other side. Check bad connections to the ground as well. The ignition switch is a wrong path however. Always on circuts don’t use these connections.