possible bolt in alternators

[1978freebornred]

I know that it has probably already covered on here but I am looking for a higher output alternator for my 78 fj40 I just put in a new wiring harness from painless so it can withstand more amps than the stock 45... ive got a few more accessories than stock like kc lights, arb air compressor, and stereo and if i have multiple things goin at the same time one of the loads shuts off or dimms... I would appreciate some suggestions for bolt in high output alternators with little fabrication... thanks.

 

[imabigbangkindaguy]

mean green alternators

 

[1978freebornred]

so mean green alternators is that a fj40 specific brand?

 

[bikersmurf]

No, but they make one to fit a 40.
MAF Mean Green Hi-Output Alternator

I'd just use a 100amp large bodied chev alternator. Plenty of power for what you're talking about... And won't set you back $400.

I googled it and found this thread,
https://forum.ih8mud.com/40-55-series-tech/323883-gm-alternator-78-fj40.html

And there are many others.

 

[alkarich]

From the FAQ section (tons of greta info there):

https://forum.ih8mud.com/40-55-series-tech/120946-gm-alternator-info-faq.html#post1569709

Alan

 

[bsevans]

I have the 200 amp CS144 alternator from Mean Green and I love it. I recommend that you call Mean Green and purchase it with the double pulley so you have more options for belt driven devices. If you still have the smog pump, then you will need to run the alternator on the outside pulley.

 

[FJ40Jim]

The first upgrade is the 55-65A electronic regulated alternator for 79-87 2F.

Top bolt in upgrade is 80A electronic alt from 88-92 3FE.

Rumor has it that there is an even higher power alt on some T100 or Tundra trucks that will bolt on to the 2F bracket, but I haven't seen it.

 

[numby]

I have a 79 55 amp model in my 78. I can't say it made a huge difference but it does seem to recharge a drained battery a little faster than the 45 amp model. No real difference at idle. My wipers and lights still dim.

 

[subzali]

<snip>Rumor has it that there is an even higher power alt on some T100 or Tundra trucks that will bolt on to the 2F bracket, but I haven't seen it.

I got to thinking about this, couldn't be a 4.7L Tundra because of the serpentine belt, so would have to be the 3.4L V6 alt because of the v-belt. Which would mean T100, 1st gen Tundra, 1st/2nd gen Tacoma, and 3rd gen 4Runner, right?

...Unless the engines are the same, but accessories are different due to different applications...

I'll need to take some measurements...unless someone has one handy they can plop out and back in quick and could check it?

How do you find out the amp outputs of OE alternators? What would the amp outputs be of those OE alternators?

 

[Mark W]

Swapping a pulley is usually still considered "bolt in".

Divide the wattage by 14 to get amperage.


Mark...

 

[subzali]

Where is the wattage rating found? Is it stamped on the alt.? Or do you have to have factory lit.? Sorry I'm dumb...

 

[Mark W]

You will seldom find an alternator rated in watts. Amps is what you will be given. Figure the wattage by turning the math around the other way.

Alternators are not stamped with outputs. Sometimes it may be shown on a tag. More commonly you just have to know/find out what a particular model puts out.


Mark...

 

[FJ40Jim]

If the OE application of the alternator is known, then it can be looked up in a parts catalog, like Rockauto.com, to get some specs, like amps, VR type...