Charging problems

Never,never take the battery cable off when the engine is running. the voltage surges are death for computers.

overcharging is the cause for the battery failing and also the alternator. a factory replacement is most likely the answer along with a new battery. then monitor voltage at the battery. it should be 14 to 14.5 volts

Roy

Read the article below, it will help

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Charging system wiring diagram is attached below

You're going to have to explain that. The starter solenoid can't "draw power" if the circuit is turned off. If the contact disc in the solenoid were to stick, the starter motor would continue running after the ignition switch was released from the "crank" position. You'd hear that. Some manufacturers use the larger battery terminal on the solenoid as a convenient tie point for other circuits, to save on wire. The generator's output wire is commonly connected there. I don't know this for a fact, but I have a suspicion there was an intermittent connection there, and removing the wires, and reinstalling them, overcame that bad connection. If that is what happened, you would have also solved the problem by removing and reinstalling the original starter.

As I said, I would need a better explanation from the mechanic. I taught Automotive Electrical in a community college for over nine years, and was an electrical specialist before that for 16 years. There is no way I could make this a case study without knowing the rest of the story. A circuit that is turned off can't draw current. The ignition switch or the starter relay, when used, would have to stick on to continue to allow current to flow to the starter solenoid, and if that happened, you'd hear the starter running all the time. I appreciate you adding your findings to help the next person, but there are a pile of more-common causes for intermittent charging problems.

Yes, I feel that way too, but that is not my intent. A lot of people read through these posts before posting their own question. I can't think of a logical way troubleshooting steps could lead to the starter for a problem in a totally unrelated circuit, and I want to avoid having people run out and buy a starter thinking it's going to solve a charging system problem. I would step in too if someone said they solved an overheating problem by replacing a brake light bulb.

I'm not denying your problem has been solved, but in my experience, when asked to interpret repair bills, I've found too often that mechanics present their own version of what "solved the problem". That is USUALLY not done to defraud. It is done to simplify the explanation so the average car owner will accept it, and the mechanic can get back to work on the next car. I would be much more willing to accept your explanation if you had done the diagnosis and repair yourself. Mechanics, just the people in many other professions, have very poor communication skills when working with car owners. A lot gets lost in translation.

I've had similar problems with my own vehicles. One in particular was what acted exactly like an engine with a carburetor running out of gas. I fought that intermittent problem for a year and a half, until it finally failed completely. Turned out be the ignition coil. I never once had loss of spark when the problem occurred, until that total failure. There is no way I can allow the next person to think they are going to solve the same problem on their vehicle with the same solution. In this case, no expert has ever guessed the cause when I presented the problem, and it wasn't until the cause was known that a believable explanation could be figured out.

Again, I would never expect this to apply to another vehicle, but thank you for including your information. I WAS wrong once before, ... In 1969. I thought I had made a mistake, but found out later I didn't, therefore, I was wrong.