Alternator smoking after jump start...

Do you guys have any links to support this claim of not running the alternator when jump starting a vehicle. According to you guys I have been doing it all wrong for about 50 years with no issues. I must be really really lucky.



I should go buy some lottery tickets.

 

https://driving-tests.org/beginner-drivers/how-to-jump-start-a-car/

Have The Driver Of The Vehicle With The Good Battery Turn Their Engine On And Allow It To Idle For A Few Minutes.

https://www.pepboys.com/auto-care/maintenance/jump-starting-your-car

Start the engine of the good car. Allow it to run for 1-2 minutes. Rev the engine slightly by pressing on the gas pedal lightly.

https://resource-center.meineke.com/jump-start-car-battery-right-way/

Start the working vehicle. Wait a minute or so. Depending on the age of the battery and how long since it died, you may need to let the car run for a minute or two to get the jump to work.

https://www.popularmechanics.com/cars/a24902/how-to-jumpstart-a-car/

Start the functioning vehicle first, then try to start the dead vehicle.

 

Checkmate.

 

Old guy(s) for the win!

 

Yeah no kidding, I must have been doing it wrong and destroying alternators my whole life from jumpstarting...

I make a small engine alternator kit for this particular usage.

www.affordabledcgenerators.com



I have yet to pop one putting it on a dead vehicle, running it for a few minutes, then cranking it over. Not once.

 

I’m curious if, since it had 2 batteries, was it a 24 volt system? I’ve seen many on big rig Diesel engines and industrial engines. I’ve never played with a diesel street vehicle so I don’t know if they run 24v.

I jump start all kinda dumb ways. Sometimes, the dead vehicle is inaccessible so I have 2 jumper packs. A pos antigravity, and a newer batteryless jumper. If it’s say less than 4 volts, the 2 will get it started. Then I can move it to see what’s up. I even once tried 2 extension cords holding them against the batteries, of course it didn’t work.

I have seen a battery explode in high school auto shop. The teacher was trying to jump a car, he grabbed the loose terminal and twisted it, it sparked and the battery went pop. Got acid on my friends face.

My favorite was when, after jumping a vehicle, I tossed the cables across the cab, it hit the shifter and took off with me running after it screaming OOOH SHIIIIIT.

 

https://www.youtube.com/watch?v=xNOjEuyRRO0 Yes, I know it's Scotty Kilmer but sometimes you can learn stuff. He mentions it at about 1:35.

 

1. The likely scenario is that your alternator was on its last leg and just happened to give up the ghost when it was working to recharge your battery. The fact that your alternator was covered in oil, grease, and other shizz, prolly did not help the cause. Either way, the engine draws from the battery. No way the diesel was the direct cause of your alternator frying. Only way I have seen that is if the poles were crossed.


2. Yeah, there is no truth to not having the working car running while jumping. Having it running is advised even in the Toyota Tacoma manual that way. So, Toyota engineers are advising you to have the working car running while jumping your Tacoma. See below:

“Start the engine of the second vehicle. Increase the engine speed slightly and maintain at that level for approximately 5 minutes to recharge the battery of your vehicle.
Vehicles with a smart key system only: Open and close any of the doors of your vehicle with the engine switch off.
Maintain the engine speed of the second vehicle and start the engine of your vehicle by turning the engine switch to the “ON” position (vehicles without a smart key system) or IGNITION ON mode (vehicles with a smart key system).
Once the vehicle’s engine has started, remove the jumper cables in the exact reverse order from which they were connected.

Once the engine starts, have the vehicle inspected at your Toyota dealer as soon as possible.“

 

Another vote for a NOCO, but don’t waste your money. The GB20 will do fine for most cars and non-huge trucks. If it can’t start a very large vehicle, then oh well. I feel like they should have their own recovery gear at that point.

 

Watched video, learned nothing.

Have two alternators running against each other? Nope.

And I have to mention that guy is a loon.

What you have is two batteries connected in parallel with two alternators charging them for a brief moment. You shouldn't leave them connected while both are running as there is no point to it. As soon as the dead car is running disconnect the jumper cables.
The batteries job is to act as a buffer between the alternator and the load circuits.

 

Yes. And the first thing you should buy is a 3rd Gen.
Because we know you’d fit in really really well over there in that forum.
After all, you are way over due for a “blow from the ban hammer”.

The real issue was he needed a bigger engine to jump the Ford off.
I’m pretty sure you you can handle the DIY on an engine swap for him?

 

I refuse to talk about engine swaps ever again.

I guess its like telling your wife she has put on a "few" pounds.

 

Oh I am so sorry to hear this . However, very cool that you helped a fellow motorist. That is really a bummer but nice to hear that you were trying to help someone who was in need. I live in N. Michigan and we have pretty tough winters. It is a really rural area, small community, lots of farming. The consensus for a long time is when you see someone who got stuck or went off the road or hit a drift, you stop and give a hand. Try to pull them out or push them out, etc. That has been changing in the last 10 years with people just not stopping anymore or ignoring. Maybe it is the influx in people moving to our area from larger cities or it might have to do with people being afraid of getting sued if something goes wrong? Hope it all worked out and you got a new alternator. Maybe it was weekend and just waiting to go anyways?

 

I don't think there are any civilian one ton and lower trucks with a 24v system in America. You may find plenty with dual batteries and dual alternators but still 12v.

Only thing I can think of are military spec CUCV trucks from Chevy and Dodge. They are 24v systems using double of everything but only the starting and glow plug system is 24v, the rest of the truck is still 12v.

 

My old diesel cruiser is 24V, but is is a Canadian rig.
Primary benefit of a 24 V system is being able to reduce wire gauge - weight and money - for long wire runs. Throw more V at it so you need less I. Less I lets you got with more R on the wire - smaller gauge.

 

That is pretty cool, what are the specs of the cruiser?

Is the entire truck 24 volts or do they step it down with some type of converter?

 

Factory 24V. Bit of a Frankencruiser 87 FJ60 with 1990 HD1-T Inline 6 Diesel. Quite the goat.
The 24V aspect is a bit of a pain as most cool stuff is 12V. So yo need to take a 12V tap off one of the bats to run an aux panel and place a battery balancer between to the two bats to avoid overcharging an unbalance sys - the 24V alt does not care if one bat is at 10V and the other at 14V it just put 24V across the stack.

 

Cool

Never seen a 24v Cruiser in person. The only diesel Cruiser I ever worked in was a Canadian 40 series that was imported. It was 12v

On the CUCV, we have a pair of isolated ground alternators in series so you can take 12v from either one no problem.

 

OP: You didn't do anything wrong. As others have said, I suspect your alternator was on its last legs and asking it for full output caused it to fail. This is the most plausible explanation.

• Modern alternators are current limited via electronics and design. They're not going to exceed their rated amperage output no matter how much you demand of them. They don't say, "Well, I'm only rated for 130 amps, but you asked for 1000 amps so here you go and I'll kill myself doing it." Remember, when you connect your donor battery to the depleted battery, the donor battery starts to discharge. It then begins absorbing electrons from the alternator. Your donor alternator is simply charging the donor battery like it always does.
• Even if one considers the fact that connecting the donor battery to the dead battery in parallel now makes the electrical system see both batteries as a single large battery, the donor alternator isn't going to suddenly start outputting more electrons than it's rated for.
• No, there's no problem leaving the donor vehicle running while jump starting a dead vehicle. In fact, it's a good thing: It is contributing electrons to the process along with the donor battery. Modern alternators don't magically become stupid and kill themselves just because they sense the need for full output due to the donor vehicle's discharging battery. If that were true, then every time someone jump started the depleted battery in my Taco, the alternator in my Taco would burn itself up and fail while attempting to charge its own depleted battery. In that scenario, my Taco alternator does get frickin' hot as it outputs its full power to charge its own depleted battery; however, the alternator will only fail if there is an unexpected component weakness or failure within the alternator.
• Connecting to a grounding point on the dead vehicle rather than the battery's negative terminal serves only one purpose: It gets potential sparks away from a dead battery that could be venting hydrogen gas.

I suspect that your alternator would have smoked in the same fashion if you yourself had required a jumpstart for a dead battery. Your battery would have demanded full recharge output from the alternator and your failing alternator wouldn't have been able to meet the demand.

So jumpstart away. Positive to positive. Negative to a groundpoint (for safety). Vehicle on. Rev up the donor vehicle to get more output from the donor alternator. Wait a minute or two and then crank the dead vehicle.

 

I'm looking at everything as I roll up, and sometimes I just roll on by. Dealing with stressed people can be a problem. If everything looks ok, I'll whip out my Antigravity jump pack, which incidentally hooks up directly to the battery.
Everyone has a phone these days, so a call has already been made for help. It's not the big emergency it used to be. A woman for instance, probably won't even crack the window and talk to you.. sad sign of the times. Guaranteed both hands won't be on the wheel, so be carefull.