in the late 90s / early 2000s when I was a lowly GM guy, i had a few alternators beefed up locally. I have been wondering if this is still a viable option, has anyone used D & D auto electric?
https://g.co/kgs/3PR1sF8 Is this even possible for a yota alternator to accept more windings and brushes?
I had Doug at D and D put the guts of an 65A FJ62 alternator inside of my 55A FJ60 alternator case. The 62 isn't a direct fit into the engine bay of a 60. He can rewind stuff or do whatever.
@On the RX In my searches for alternator solutions for a 60, a lot of folks go to the BIG alts with lots of "POWER", but then don't have much or any improvement at idle. Most alternators are just fine once you're spinning the engine up, say driving on the highway, but all of them can put out less current at idle. The thing to look for is the alternator's curve. How much current can it supply at how much rpm? One way to skew the entire curve is to change the pulley size. Slightly smaller gives you more current capacity at all rpm including idle - but the alt runs hotter at higher rpm. Larger pulley skews the current capacity lower at all rpm - but the alt will run cooler.
For me, even the wimpy 55A alt that came with 60s puts out enough power for 99% of my needs - but not at idle. To improve idle current supply I looked at the whole system. Sorry this maybe isn't as easy as you thought. I upgraded almost every single ground cable on the truck to 2 or 4awg and cleaned all the contact points and bolts. I installed larger 12V wiring where necessary to cut down on line resistance. I installed all LED lighting inside and out except the headlights, so at night (when you use more accessories), I wasn't having a ton of draw from a million little bulbs. I installed a larger alternator charge wire and that made probably the most improvement. Stock was 12awg and I went to 6awg. It has to be fused. I have almost a full 1.0V higher at idle because of the healthy supply current from the alternator to the battery. I do have a pulley that's 5-10% smaller but I haven't installed it yet.
My biggest draw is 30A of halogen lighting on the front of the truck, which is usually only used when wheeling at low rpms. If I get much below 1000rpm I have to shut half of those lights down. If I had a 150A alternator it would still be kicking out a similar amount to my 65A alternator at 1000rpm so there's not a whole lot I can do from here. At 2500rpm the alternators will have a big difference in supply current - closer to their 65A and 150A rated values. But during normal driving I don't have a problem running my big lights up front because my alternator is running faster and able to supply plenty of current - so what good would an extra big POWER alternator do for me there? Not much at all. I'm also running a small bit of aftermarket stuff like you are, and a lot of times at night I'll have the front and rear heaters blowing, rear defrost and wipers going if necessary, etc. I can really have everything in the truck going full bore - including the big lights up front - and have zero issues at idle ... on a 65A alternator. That's cruising at 20-70mph.
Obviously if your alternator is dying you'll need a new one - doesn't hurt to take it to D and D in Wheat Ridge for a rebuild by a local expert and ask about a rewind or pulley upgrade. Or try out an off-label use alt like Daniel suggested if you don't mind whatever mods it takes to fit. That Tuscon one is likely using a smaller pulley to adjust the curve, hence the smaller belt, but whether or not they're doing any internal modifications who knows. On top of the new alternator, I'd recommend upgrading and cleaning your grounds and installing a larger alternator charge cable that's fused properly. That's going to make a huge difference at idle where it matters. Oh, and maybe your failure is the voltage regulator, can you try replacing that first rather than the whole alternator?