Alternator Options

my 70 cj5 has a 225 v6. I am having some cold weather issues with starting this morning, nothing the charger wont fix, but it got me thinking about electrical system upgrades.

is there a semi drop in 130 amp, or similar, option so i can run? i plan to add an electric fan, winch and a few lights on the old girl.

 

Have you done a search? There should be many posts relating to installation/wiring of GM 10 si/12 si alternators. Very easy conversion.

 

my searches never seem to include the correct terms. will look up the 10/12 si

 

Mmm. Correct me if I'm wrong, but a properly functioning 35 amp alternator will keep your battery charged just as well as a 200 amp monster. I would look at the batery's condition first, and the cables, and check for something that's draining the battery. Faulty alternators can drain the battery, but that's because the alternator is broken, not because it's not strong enough.

 

I think my ElCheapo Auto Zone 1 wire is 67Amp? and it keeps up with winching and trailers and what all. No issues since owning it.

 

What I have done is take the Motorola alt to the local rebuilt shop or knowledgeable auto parts supplier . They can match up the correct case of a Delco unit so it,s a drop in deal in either three wire or one wire.60- 90 amp should be fine without putting undo strain on v-belt. My 35 amp Motorola works fine after rebuild but no extra load except winch.

 

In my experience with similar problems I'd suggest as timgr said first checking the battery and clean connections, the fan belt for proper tension, fit, and wear.

 

I have a standard GM 10si on my Jeep, around 60 amp, or so I am told. My Jeep had a Motorola alternator and regulator on it that was not working. I bought a GM one wire at a local auto parts store, set it on the Motorola bracket and lined it up with the front pulley on the f 134, figured out that I could cut about an inch off the back of the GM alternator and it lined up with the front pulley on my motor. I made a spacer for the adjustment arm to move it forward so it lined up with the alternator and it worked out great so far, that was in 2007. I put an amp meter on it so I could see how much it is charging, it starts charging as soon as I start driving it, no problem. I now made a bracket that will accept a GM alternator without cutting the housing, and am going to put a GM 12si on it so I can make the charging light work. I found a 5/8" pulley on line and can use the larger belt 5/8" factory belt on it. Hope this helps, Good Luck

 

I don't get it. Why cut the case down? My 10si fits with no modifications of the case. Was already on the JEEP when I bought it 12 years ago. I have changed batteries twice since then, which is actually really good. Most batteries don't last past 4.5 or 5 years, anyway.

 

I needed to up the amperage output because of my electric fan. Went one wire GM unit. Its just not a big deal to wire the regulator externally. The internal regulator is not such an upgrade that it really mattered to me other than the ease of finding the GM one wire. Even those alternators are old now.

 

If you are thinking about switching to a 10SI, Mad Electrical has a couple of articles that may be helpful -

Catalog
Catalog

IMO the 3-wire is so easy to connect, there's not much reason to go with a 1-wire. Every parts store will have a suitable 3-wire in stock. Don't worry about clocking - you can easily clock the 10SI and 12SI to any direction using a toothpick to hold the brushes in.

 

There must be different 10SI cases, like I said when I eyeballed it the two pulleys didn't line up. The case has plenty of mounting bracket so cutting it down didn't hurt anything. I just looked at another 10SI in another article and it was different than the two I have ??? Good Luck, Rick

 

Very cool Tim, that explains everything, Thanks for posting the catalog. Rick

 

Well darned if I didn’t just go through the exact same thing, maybe a few weeks back at the longest.

Bought a 12si from Powermaster, idling at about 90amps+ and added a universal alternator bracket (which you can pick up many places). Upgraded a lot of wiring as well, and like MAD Electrical says, put some in-line fusible links in the harness.

The lights are brighter, she starts stronger, and reads 14+ volts at idle. What an improvement.

Do not leave an old ammeter in the dash with a high-amp alternator! Serious fire hazard is possible. Luckily mine just kind of melted, instead of balls-out electrical fire.

Oh, and X2 on the battery. Even the supposedly top-tier batteries last only a handful of years.

 

I had a 130 amp alternator made at a place called Autolectrics. That was quite some time ago. They charged "a buck an amp" back then. I have heard they were sold here and the quality is not the same any longer. Might be something to look into.

 

I agree ..I had to do the same thing,on a 74 cj with a 232 ci . but when I got a later 258 ci (1977) . It fit without cutting.

 

I have the radiator off my Garage Motor, I can show the bracket I made for my GM one wire.

 

Found the source for 5/8" pulley for a one wire, the one I found is, Howard Enterprises, in Ks. about $20.00, (602) 228 1477. He is on E-bay

 

I said that number wrong, it's (620) 228 1477, sorry about that.