High output alternator?

I'm just curious, my alternator works okay now, but I have it in my head that I'm going to take a little money out of each paycheck and replace things that could possibly go wrong while I'm off-road in the near future. So far, tires, water-pump, radiator repairs, water hoses, all new brake components, battery, carb overhaul, belt, grease job, oil in the diffs, gearbox and transfer have been tackled and almost completed.

Just eyeballing the alternator though, it looks rusty and tired, even though I haven't noticed a charging problem nor have I had it tested to see what the output was. So I was wondering, if we're going to be using the jeep allot at night chasing these Texas hogs and hunting with lights quite abit, and if I were to replace the alternator now, should I request an alternator that has a higher output? Is that even possible?

One one hand, I don't have an air conditioner or really anything that uses that much energy, but when I add the hunting lights, winch, and feed spreader on the back, do you think I should be concerned about the alternator's ability to keep my battery charged or just go with the OEM replacement at my parts store?:?

 

I would replace it with an internally regulated 1 or 3 wire GM style higher output. This will get rid of a lot of the messy wiring under the hood.

The extra load you are talking may or may not push the current on over the edge.

 

Not sure about '74, but AMC started using the Delco on the 6-cylinders somewhere in that era. The V8s carried on with the Motorolas for a while.

If you have a Delco alternator already, it may be as simple as replacing the existing alternator with a higher output unit. Jeep offered a "heavy duty electrical" option, which included a higher output alternator and battery. Swapping to a Delco would be a good idea if you have the Motorola alternator - the Delcos are more reliable and have the regulator internal to the alternator.

 

Check in with some of the emergency vehicle builders on the internet and see what they are using. The lighting requirements on fire trucks are exceptionally high and require some high output alternators. Leese-Neville seems to come to mind as a brand of HD alternator from back during my rescue squad days.

You may also check your local heavy truck dealers parts department. They have access to the bigger capacity alternators too!!

If you want to stick with the Delco brand, the 12si is a 105amp 12v unit that you can expect to spend 100 bucks on. I'm not sure what they would have been installed on from the factory, but if you could find this out and hit the bone yards you may find one fairly cheap. 105amps should make a great welder.

 

I agree with upgrading if you don't already have a heavy duty unit. The 12 si was used on some trucks and lots of GM luxury cars like Cadillacs because of all the electrical gadgets they had. Be aware there are two case sizes on 10 and 12 si alternators. Small and large. Make sure you get one that matches the dimensions of your bracketry. Nickmil

 

I've got a 105 amp delco 3-wire on mine. Wiring is nice and clean, its readily available at your FLAPS, and it seems to provide more than enough juice to charge my optima after winching.

I even got the napa gold with the lifetime warranty, if it burns out (translation: filled with mud or water, i get a new one.

 

I've got the original alternator on my 75. Works fine with my occasional winch use, don't have any extra lights though.
I scraped and scrubbed the thing and found markings on it that indicated it was a Delco 10si, 63 amp. I would suspect that the 63A 10si was the HD option, as it is the largest amp alt listed as stock in my 75 FSM.

So check your current alt, you might have gotten lucky.

Another thing to keep in mind is that the more amps an alt puts out, the more of a strain it places on the engine and belt drive components.
Not a big deal if you stay at 105A or less. I've heard some complaints about the really big amp alts, though.

Were I winching a lot, I'd get a second battery, and keep my present 63A alt. Batteries seem to be happier if they are recharged slowly. Craming big amps (140+) down a discharged batteries throat on a regular basis will make for a shorter lived battery, unless the battery was designed for that kind of use.

As in most things, there is no simple, "right" answer. It all depends on your situation.

 

this may help, may not....

http://www.madelectrical.com/electricaltech/delcoremy.shtml

 

It all help! Again, you guys are awesome! Thanks for the help!

 

I am using summit racings black powder coated "SUM-811001" 100 AMP, 1 Wire.

I am very happy with it and only $90. Runs my EFI, elec fan, elec fuel pump, heated seats, headlights. All with no problem.

 

Theres one sitting in it's box in my shed waiting for installation once the engine swap is done. Seems to be an excelent unit, and the powder coating makes it tougher (somewhat).
Once the winch and extra lights go on,,a dual-battery system is coming along with them.

If you have anything less than 70 amps or so,,,definately upgrade, if for no other reason than keeping the battery healthier,longer, as discharging too deeply(Lots of high-output lights on for long periods and repeated winching) too often will shorten it's life.

 

Late 80's to early 90's Chevy Astro vans have a nice small Internal regulated 90amp if you can modify your brackets of fab new ones. I have one on my FC170.

 

Nice link Mr. Therapy. Another keeper. You guys never cease to amaze.

 

I had one given to me from a '95 Astro van and the parts guy, a buddy, took it as a core and gave me one clocked like the old 63 amp Delco I had been running. For the Jeep I had to modifify the existing lower bracket to make it wide enough for the Delco. I think novaresources had the wiring diagram.

 

GM one wire here... only issues i had was that the alternator cooling fan on the new alternator was bigger so i swaped them out instead of going through the trouble of removing the alternator bracket and cutting it...


other issue was...... what to do with all the wiring that came off the jeep after the alternator swap R)


*after i did it i was kicking my self in the but for not doing it long ago :twisted:

 

12SI is a great way to go. I picked mine up at NAPA..new with a lifetime warranty. I think it is a 95 amp and I got it in the three wire configuration per the MAD Electrical recommendation. Haven't had any problems since the upgrade and the OPTIMA stays at full charge.

Here's another good link to the same site.........

http://www.madelectrical.com/electricaltech/onewire-threewire.shtml

 

If you've got a Crapola, uh um, I mean Motorola alternator I HIGHLY RECOMMEND retrofitting with a Delco!

 

I went with a 130si per the counterman at the local alt shop (does better with high under hood temps). I had a 180amp one, but it fried 2 batteries before it died, and I replaced it with a 110amp and haven't had any issues since.

I would also go with a large (group 27ish) marine battery. thy seem to last long with high drain accessories and winching duties.

 

I agree, great info!

I do have the motorolla 53 amp on it now. I'll see what I can do about that! Thanks for the help again fellas!