Is the suggestion in the following video correct, or dangerous to car electrical components?

[leadfoot6]

I am making my first post here at this forum, and it will soon become obvious, but in line with the material I have recently seen on joining this forum, I AM NOT A QUALIFIED AUTO ELECTRICIAN(but hoping to be allowed to post in this sub-forum), just a reasonably experienced home mechanic who is more confident fixing mechanical issues, but less so with issues involving auto electrical components.

Are there any comments about the following short video?

He removes the positive/+ve battery terminal when the engine is running.

I remember that it was OK to do this on older cars, but AFAIK it was not to be done on modern cars as it might cause BIG problems with the ECU and/or alternator.

Comments welcome, particularly dealing with 2004 Mitsubishi Magna/ aka Diamante(USA).

There are comments either way in the comments attached to the video.

This is very confusing.

The reason I am asking this is that I am trying to find a cause for my older battery(4 years old 10 days ago) going flat with no obvious indications before complete failure, and the "like for like" replacement battery likewise going completely flat after 1 week.

The alternator/battery light has never illuminated at all when it should not do.

It illuminates prior to start, and extinguishes once started.

Terminals are tight.

Belt seems to be tight, with no slipping noises.

The brand of battery (both times) is the Australian made Century "Ultra High Performance 67 EF MF" model.

67EF MF - Ultra Hi Performance Conventional car batteries | Century Batteries

67EF MF - Ultra Hi Performance Conventional car batteries. Special features: Carry Handles, Central Venting, Flame Arrestor, Made In Australia, Maintenance Free, Mud Rack, State of Charge Indicator.. Warranty: 40.

www.centurybatteries.com.au

Century Batteries have an excellent reputation in Australia.

It is the biggest size/capacity battery that will fit without modifications, and has 20% greater CCA(640) than original factory fitment.

I would appreciate some troubleshooting tips shortly, but I would appreciate if the contents of the video can be addressed and discussed comprehensively first.

Thanks.

 

[telectrix]

need to measure the output from the alternator. should be 14+V with engine running on high tickover. measure at battery tertminals.

 

[leadfoot6]

need to measure the output from the alternator. should be 14+V with engine running on high tickover. measure at battery tertminals.

Thanks, but I would still hope that someone is able to answer my initial question about the video.

I was going to pose further questions about troubleshooting after the question had been answered by those with experience and certain knowledge.

 

[brianmoooore]

1) You're pushing your luck, for both the donor and receiver, using jump leads on modern car.
2) You should always remove the negative connector to a car battery first.
3) Disconnecting the battery on a running engine will always cause a voltage spike. which again means you are pushing your luck.

Flat battery causes;
1) Dud battery.
2) Dud alternator.
3) Problems with the large cables between them, especially on the earth side of things.
4) A drain on the battery when the car is switched off, as a result of a fault.

 

[leadfoot6]

1) You're pushing your luck, for both the donor and receiver, using jump leads on modern car.
2) You should always remove the negative connector to a car battery first.
3) Disconnecting the battery on a running engine will always cause a voltage spike. which again means you are pushing your luck.

Flat battery causes;
1) Dud battery.
2) Dud alternator.
3) Problems with the large cables between them, especially on the earth side of things.
4) A drain on the battery when the car is switched off, as a result of a fault.

Again, thanks for the reply, but are you able to address my question as to the correctness, or otherwise, of the video that I posted in the first post?

 

[brianmoooore]

The three points I made are three things he did wrong. I do not have sound for the video.

 

[leadfoot6]

The three points I made are three things he did wrong. I do not have sound for the video.

Here's a link to the video:MEDIA=youtube]UN2EwLPT2No[/MEDIA [outer brackets deleted to allow most of the code to show]

just add the [ ] brackets on the outsides

The sound works for me.

The video is about 1.55 long i.e. not long at all.

 

[brianmoooore]

Laptop I'm using doesn't have working sound.

 

[Avo Mk8]

sound worked for me on a tablet!
(I'm talking about the video in post #1)
From the part where he re-connects the battery and then measures its voltage, that is all true. voltage change depends on the condition and state of charge of the battery.
My personal view is I would not do the first part, which he claims "works on most vehicles". What about alarm starting, losing security codes etc, if the alternator is faulty?
It might be OK on older cars.

 

[leadfoot6]

sound worked for me on a tablet!
(I'm talking about the video in post #1)
From the part where he re-connects the battery and then measures its voltage, that is all true. voltage change depends on the condition and state of charge of the battery.
My personal view is I would not do the first part, which he claims "works on most vehicles". What about alarm starting, losing security codes etc, if the alternator is faulty?
It might be OK on older cars.

Yes, I tend to agree, but he is so insistent that his method works.

I was hoping that it did for later model cars, but I don't think it is worth the risk.

Are any fully qualified people able to offer other opinions?

I would appreciate it.

 

[DPG]

Have you measured the current drain when the ignition is off? Measure it after a few minutes, then do it again after an hour (modern cars often leave some systems running for a while before full shut down).

 

[leadfoot6]

Have you measured the current drain when the ignition is off? Measure it after a few minutes, then do it again after an hour (modern cars often leave some systems running for a while before full shut down).

Now that I know that I am best off not to have any reliance on the troubleshooting method in the video, I will start using other, more conventional, methods to find my problem.

I imagine that you are referring to "parasitic current"?

I will update probably tomorrow(it is now night time).

 

[DPG]

Now that I know that I am best off not to have any reliance on the troubleshooting method in the video, I will start using other, more conventional, methods to find my problem.

I imagine that you are referring to "parasitic current"?

I will update probably tomorrow(it is now night time).

Yes indeed. It will be good to at least eliminate the basics.

 

[leadfoot6]

Yes indeed. It will be good to at least eliminate the basics.

Thanks for that.

I will look at some videos as to how to do that.

As soon as I acquire auto electrical knowledge and use it, I forget it shortly after, mainly because fortunately I do not have to do much of it so I get "rusty", so I will need to start again from scratch.

 

[DPG]

Thanks for that.

I will look at some videos as to how to do that.

As soon as I acquire auto electrical knowledge and use it, I forget it shortly after, mainly because fortunately I do not have to do much of it so I get "rusty", so I will need to start again from scratch.

Remember to avoid the mistake often made where people set the multimeter for current measurement and then proceed to connect it across positive and negative! Remember, current measurements are made in series.

And if it's not auto-ranging then start on a higher range and work down.

 

[leadfoot6]

Remember to avoid the mistake often made where people set the multimeter for current measurement and then proceed to connect it across positive and negative! Remember, current measurements are made in series.

And if it's not auto-ranging then start on a higher range and work down.

Thanks for that information.

I will try to get organised later today.

 

[R-fur]

I think the guy is talking sh!t. You are more likley to cause problems doing what he says. Far simpler to just check the voltage across the battery, should be about 12V with the engine off and about 13.8-14v with the engine on. If the voltage is much below 12 with the engine off then the battery is faulty, if the voltage doesent rise with the engine on then the alternator is faulty.

 

[leadfoot6]

I'm sorry that I have not replied sooner.

Thank you to those taking the time to respond.

My car is now running properly again after I had a genuine Bosch alternator fitted.

NEW GENUINE BOSCH ALTERNATOR MITSUBISHI MAGNA & VERADA TE TF TH TJ TL TW & KE | eBay

Mitsubishi Magna & Verada V6 (6G72 & 6G74). Mitsubishi Verada KE, 1996-1997. Mitsubishi Magna TJ, 2000-2002. Mitsubishi Magna TF, 1996-1999. Mitsubishi Magna TW, 2004-2005. Mitsubishi Magna TE, 1996-1997.

www.ebay.com.au

In the meantime, I had to get by just by "jumping"/recharging/only driving short distances.

I did not want to risk driving further than the local small town and risk the battery going flat between towns.

The multimeter now reads 14.7v at idle.

No other work(fuses/relays/check/adjust drive belt - all OK) was done.

Starts/runs fine for the last week, after being off the road for almost a month as it was difficult to:

a. Get the genuine part at the "right" price,

b. Have it delivered to my non-urban address,

c. Have the extremely busy local(competent/honest) mechanic have the time to fit me in.

1 hour labour charge = $120 AUD.

My question is why the alternator warning light did not illuminate from the beginning of my problem?

It took 2 weeks or more of the battery going flat before it started glowing continuously when the engine was on.

A brand new alternator fixed the problem, so I am wondering why the alternator light did not start illuminating right from the beginning of problems.

Thank you again to those who responded.

P.S. I did not get around to doing any voltage drop tests, or try to delve too much into problem solving.

I just went and had the complete alternator swapped out, and it has turned out to be the correct solution

 

[Simon47]

So much boolocks in such a short video
If the battery is flat enough that you need to jump start, removing a battery connection with the engine running is liable to create a massive voltage surge that can blow your electronics (including the alternator).
Also, don't remove the negative - always remove the negative first and connect it last (assuming, as I believe all modern cars are, negative earth). That way, if you touch the bodywork with your spanner, it's not going to short the battery out and make a big flash. As we al know, it doesn't matter which end we disconnect - it still disconnects the circuit.