Alternator smoking after jump start...

Well, kinda.

The Taco's alternator had a much larger demand on it when connected to the two large batteries versus the one smaller battery it's designed for. Sounds like OP was using his alternator to charge the diesel's batteries instead of using his battery to provide the power to start the diesel itself, which is how the jump should have been done.

So OP smoked his alternator by running it under full load for too long trying to charge the big batteries, batteries which will happily draw as many amps as can be provided. Poor little Taco.

 

Exactly.
Factor in the resistance of the jumper cables. you can see why the Taco had issues.
The Taco had to be hooked up to the diesel for hours to recharge the batteries to properly light off the diesel engine.

 

I see why you are a land rover master tech

 

Agreed. It's an alternator thing not a battery size thing. I suspect the diesel Alt is only spec'd at 140 amps or so. Still surprised the Taco alt smoked. Not sure what the duty cycle is at max output, but I would have guessed something close to continuous?? I'd be curious why the F250 bats were dead and whether or not he had a shorted cell in or two in his system.

And all this talk about grounding to the frame during jumping..sure, whatever...but the hydrogen bomb risk is negligible.

 

Brushes melting?

 

And this is why I like having a jump n carry. Help others without screwing myself. Also good to be able to self-jump your own battery without waiting for anyone. Highly recommended.

 

you answered your own question. A shorted battery on the diesel would create an "infinite hole" of voltage that the little taco alt would try to fill

 

I jumped a stone dead 351 with a little hand held over the winter. Absolutely blew me away that it worked. Part of my travel bag now.

 

I have this one. Only have to recharge once a year. Fits perfectly in the compartment behind the driver side rear seat in my double cab, and pretty much jumps anything. Used it on some dude’s v8 ram one time and it jumped it like a champ.

$123 Clore Automotive Jump-N-Carry JNC660 1700 Peak Amp 12 Volt Jump Starter , Blue

https://www.amazon.com/dp/B000JFJLP...olid=210CAX2LL742X&psc=1&ref_=lv_ov_lig_dp_it

 

I run this and its worked wonders a few times now.
used it on a buddies diesel no problem.

https://unchartedsupplyco.com/products/the-zeus

 

This lives in my car all the time, I got lucky and when I bought it, it came with the heavy duty clips and was on a lightning deal so I think it was $60-70

$100 NOCO Boost Plus GB40 1000A UltraSafe Car Battery Jump Starter, 12V Jump Starter Battery Pack, Battery Booster, Jump Box, Portable Charger and Jumper Cables for 6.0L Gasoline and 3.0L Diesel Engines

https://www.amazon.com/dp/B015TKUPI...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

 

I used one of these in a 1000mAh model. About the size of two decks of cards. Up to 400 Amps cranking output.

Type S AC56388-RED Power Bank Jump Starter 8000mAH 350A Red

https://www.amazon.com/AC56388-Ultr...keywords=type+s+battery&qid=1588804891&sr=8-2

 

This comparison was posted in another thread. I'll save ya the 20 min and tell you the Audew comes out on top. That being said I have a GB 70 and have been quite happy with it.
https://www.youtube.com/watch?v=JN8A2nIMUWA

 

I only had it revved up for the few seconds while he was trying to crank his, and he did that a couple times. Otherwise I was idling most of the time.

The guy had his daughter spraying starting fluid into the intake while he was cranking it so I have a feeling the truck had some issues going on...looked like it had seen better days. That maybe should've been my hint to say good luck and peel out. Live and learn.

Maybe I can take a peak at what the melted one looks like before the shop returns it for a core

 

An alternator is designed to work at max load. 10 minutes is not that long. Your Taco alternator is not much smaller then what is probably on that diesel truck unless it has some commercial grade setup.

Not to mention if the Taco is idling the alternator isn't even putting out maximum current. Now revving it helps but doesn't sound like you were sitting there for 10 minutes with your foot on the throttle.

Chances are your alternator was on it's way out and this just gave it the final kick.

 

It has been on there for 275k miles...

 

it is a funny post tho'

 

you got all the good out of that ALT!

 

Starting fluid? Yikes! Starting fluid + glow plug diesel motor = boom!

 

I'm going to catch so much shit for this but once upon a time I tried jump started a friend's car at a party while I was drunk and (surprise surprise) I hooked up the batteries in reverse and melted and jumper cables and fried my electronics in my first car