Alternator Info Needed

[44me]

What brand/size alternator are 40 owners running these days. My stock 40 amp won't keep up with the winch, lights and stereo demands and I can't locate a larger factory unit.

Is the Mean Green 200 amp the only game in town? I'd like to keep the electrical system stock if possible.

Thanks for your help and advice.

 

[bandy rooster]

if you wanna keep the electrical system "stock" mean green is a good option

 

[rusty_tlc]

I don't believe you will find any practical alternator that can keep up with a winch. The best you can hope for is a faster recovery time re-charging your battery.

Example:
a Warn 8274 draws 195 amps with a 2000 # load, 275 with a 4000# load, 350 amps with a 6000# load. (Warn recomends a 650CCA battery for this winch.)

In the Real World™ you won't need this much current on a full time basis.

 

[dfmorse]

44ME;

U might try this link:

http://www.alternatorparts.com/

I don't have first hand knowledge of this equipment, but some on the list have installed these on FJ40s and FJ80s. Do a lot searching and googling.

I'm thinking of doing something similar to my 40; but there is more to this than just replacing the alternator. A really good battery and wiring will get u where u want to go in most cases. Do ur homework first.

...

 

[folsom50]

Go with a 1 wire hookup Gm model, I did that with a 60 amp 70's alt. Everything fit so well that I can go back to OEM in less than 5 minutes, not that I'd want too.

 

[Benson]

I run a CS type alternator I got from Wrangler NW power products.

20-CS120HO NEW ALTERNATOR RATED AT 135 AMPS WITH 85 AMPS AT IDLE 21-TOY SPECIAL MACHINED PULLEY 5/8 BELT
ADAPTER HARNESS
21-640-1 ADAPTERS BRACKET

Talk to Steve Schroeder as he was the guy who got me hooked up with the right parts. No affiliation, etc. Be warned - you will have some sticker shock. I'm not sure how it compares in price to a mean green setup.

Everything bolted right in to replace the stock setup to power a dual battery system. I haven't run it for long but it seems to work well so far.

HTH.

James

 

[FJ40_owner]

What brand/size alternator are 40 owners running these days. My stock 40 amp won't keep up with the winch, lights and stereo demands and I can't locate a larger factory unit.

Is the Mean Green 200 amp the only game in town? I'd like to keep the electrical system stock if possible.

Thanks for your help and advice.

There must be something wrong with your alternator, battery or charging system. You should easily be able to winch occassionaly, start the vehicle and listen to the boom box blaster and have your battery recover. Is your battery at least 650 cold cranking amps? Is the alternator charging the battery? You should measure at least 13.5 volts at the battery when charging. Does your alternator have a voltage sensing wire? If so where is it landed? You need at least a 10 gage wire from the alternator to your regulator or battery. And all connections tight.

Good luck

JB

 

[BettyFJ40]

I just got through rewiring the beast. Put on a delco type 12 SI alternator with about 94 amps. Runs well. A lot of info on Madelectrical.com. No regret on rewire or upgrade in alternator and battery. Also went with a gear reduction starter. I believe I was reading an article about really high capacity batteries (higher than optimas) that now make going with dual batteries not as necessary, assuming you don't loose all charge. May be an idea as well.

I like the idea of not filling up the engine bay with wires and battery boxes, as well as a strong dependable alternator that was affordable and I could replace at any parts store. Just what you want.

 

[green40]

Ive been reading on the madelectrical site. Lots of good info. So you went with the 3 wire setup? How difficult was the rewire for the alternator?
Thanks

 

[Trollhole]

I like the idea of not filling up the engine bay with wires and battery boxes, as well as a strong dependable alternator that was affordable and I could replace at any parts store. Just what you want.

One out of two anin't bad.

I'd rather drain the winch battery which is also connected to my hot shower, lights underneath, radio, big lights and everything else electrical and leave the other for starting.

 

[Pin_Head]

Some of the information on MAD electric is over stated or hyperbole and some is just wrong.

Specifically, their statements about the necessity of using large caliber wires to run nomal headlights and remote sensing for voltage regulators is over stated. The benefits aren't worth the effort and extra expense. Their claims about the superiority of voltage meters over amp meters is just wrong. While it is true that old style amp meters (like Toyota used up until '78) run high current wires into the cab, you have to run high current wires into the cab anyway. The differences is that old style amp meters also run a high current wire back out to the battery, so the difference is 1 high current wire vs 2. Modern remote sensing amp meters don't have this problem and they give you more information about the status of your electrical system than a volt meter can.

 

[theo]

Have to agree with Pin. I've used the writeups on Madelectric in the past but I take their advice with a grain of salt!

One issue I have experienced with my 12si (94A) is overheating of the fusible link AND of some under-dash wires. This was while the alternator was charging the starting battery that was completely dead from leaving the headlights on all day. The link was too hot to hold and I saw and smelled smoke in the cab. (Had to drive home with alt. disconnected then trickle charge overnight.)

IMO, the stock wiring is insufficient to handle two and a half times the current (or more) it was designed for. Lots of people go years and years without running their battery down to "zero". For them, there isn't a problem with high current on stock wiring because the charge rate doesn't climb to the full capacity of the alternator and stay there for a long time. (Light winching, for example, will pull lots of amps, but the battery generally recovers quickly and the charge rate falls off before severely overheating any wires.) For me, an upgrade is in order, including higher capacity charge wires and a different ammeter or a shunt on the existing one.

 

[Trollhole]

Have to agree with Pin. I've used the writeups on Madelectric in the past but I take their advice with a grain of salt!

One issue I have experienced with my 12si (94A) is overheating of the fusible link AND of some under-dash wires. This was while the alternator was charging the starting battery that was completely dead from leaving the headlights on all day. The link was too hot to hold and I saw and smelled smoke in the cab. (Had to drive home with alt. disconnected then trickle charge overnight.)

IMO, the stock wiring is insufficient to handle two and a half times the current (or more) it was designed for. Lots of people go years and years without running their battery down to "zero". For them, there isn't a problem with high current on stock wiring because the charge rate doesn't climb to the full capacity of the alternator and stay there for a long time. (Light winching, for example, will pull lots of amps, but the battery generally recovers quickly and the charge rate falls off before severely overheating any wires.) For me, an upgrade is in order, including higher capacity charge wires and a different ammeter or a shunt on the existing one.

So your saying your charging battery with the wires going into the firewall to the amp meter and back to the battery? I could see where overheating could occur. My alt is seft regulating and it runs straight to the battery isolator. And then from there I run my fuseable links to each battery. I want to run one from the isolator to the alt but am wondering what size link or fuse to use. Any idea?

 

[theo]

It's been awhile since I looked at it, and I didn't ever decide which wires under the dash got hot. (It could have been due to old, poor connections with too high resistance. Not sure.)

But I know the charge wire from the alternator runs directly to the ammeter and back to the battery. This is normal for an old-style ammeter-based system. That wire also provides power to the fuse box, which is also normal.

For you, I'm not sure I would worry about a fusible link between the alternator and isolator, as long as the isolator is built to easily withstand the full output of your alternator and the wire connecting them is adequate. Seems like you are protected already from high current draw from either battery. But I'm no expert and my experience is pretty limited. I do know I winched to my heart's content on an el cheapo isolator and 2 standard starting batteries for a few years without problems. I'd describe that system but it starts with "J".