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I have a 1986 Ford E150 cargo van. The alternator gauge needle began flicking but system still was charging. It was that way for quite a while then it would stop charging for a few minutes at a time then charge again. The alternator was only a few months old and had a lifetime warranty so I got a new one. It did the same thing. I had the system checked out and the alternator/regulator(regulator is internal) checked out as well as the battery. I replaced the regulator plug and it worked fine - needle strayed steady- for a day or two then started flickering again. Any ideas of what I should look for?
Are the lights or anything else flickering? What happens when you turn on the AC and everything electrical while it is idling and moving?
Maybe its just the gauge,... or a bad ground.
Ray, the ground is the negative (black) terminal on your battery and the opposite end where the cable attaches to the block. There might also be a ground wire from the negative terminal of your battery to the body of the alternator.
The alternator is new, not refurbished. Internal regulator. I had it checked and it is good. I checked the ground to the block and it is good. I'll have to look for another ground.
How did you check the ground? Visual inspection? If so, that won't get the job done. You can have hidden corrosion there. Take it apart and clean it to shiny metal, reassemble with dielectric grease. Then you know for sure that it is good.
Also check the ground to the body. The block ground is often fine when the body ground isn't. Should be a black wire from the negative terminal to the fender or other nearby body part. IIRC, it's next to the radiator on mine.
That done, check the alternator's ground. Most ground through the case, and there usually isn't a problem, but it's free to make sure. Again, a visual inspection isn't enough.
You can get corrosion within the battery cables too. you can test for that with a voltmeter set to measure 15vdc. Attach the meter leads at one end of the cable and the other. You'll be testing both the ground cable and 12 volt + cable separately. Any voltage read indicates some degree of resistance that you don't want (likely corrosion) Real world measurement should be less than .1 to .2 volt. If it's higher you may want new cables. You should also measure any voltage from the battery's negative terminal and the chassis. That would confirm a good bonding to frame.Test with all accessories and headlights on and during starting engine. Written guide
That video is a great example of a little knowledge being a dangerous thing. A circuit is "live" when it has voltage present. All of the tests he did were on live circuits.
The term he should have been using is, "loaded". When a circuit is loaded, the voltage drop test is very useful.
But he's wrong about "front probing". That's a very useful test. It won't tell you everything, but it will tell you something. Like all tests in all fields of knowledge, you have to understand the theory to correctly interpret the results.
Your video is a far better example but to be fair, all tests on the 2nd video had voltage applied (live circuit) otherwise you'd have no readings to diagnose. Regarding "front vs back" probing, both methods were seen in the 2nd video without an explanation to associate the terminology to either approach. Front probing= voltage testing with load device removed, Back probing= voltage testing with load device in circuit.
I would never recommend a DIY repair attempt on a hybrid or totalelectric vehicle! Voltages are too dangerous and special precautions must be employed (special footwear and insulated gloves) zap
I checked the ground on the block. It is clean. I had the engine rebuilt a few years ago and that was replaced at the time. I replaced the pos. side of the battery cable but not the neg side. I found a ground on the inner fender under the hood near the battery and cleaned it.