98runner210

I need to replace my alt. Only getting 12.3 volts. I searched and found that I can get an alt from '04 4.7 4Runner and it is a direct fit (plug and play). I would be going from 70amps to 100amps.

Can anyone confirm if this is a direct swap? If not what others can I swap with? I am aware of the 99+ 3.4 80 amp.

IS going from 70 amp to 100amp dangerous for wiring?

Thanks

Ritzy4Runner

iTrader: (1)

The only danger you need to worry about is the amount of load you put on the alternator. I do not know for certain if the '04 alternator you describe would be a direct fit (bolt up and wiring) but if it is, all you are doing is increasing the capacity of the electrical system to support accessories such as a winch, electric cooling fans, off road lights, power amps for stereo system, CB, 12 vdc outlets you add and other electrical accessories (toys). There are plenty of add-ons you can put on your 4runner and having a larger capactity alternator only makes the system safer as you don't overload the alternator. Your electrical system runs off the battery and the alternator charges it. Depending on where you take your power off the battery say by using an auxillary fuse panel or direct connection to the battery for big amp draw accessories (like a winch) or you tap into existing power leads. this is where you can get into trouble is tapping into power sources that were designed for specific loads. when you go adding things to those circuits is when you can get into trouble. By the way if your current alternator is only putting out 12VDC, you better park that thing and get it changed quick cause your battery won't be able to charge and it will die when you least need it to!

BLKNBLU

iTrader: (1)

The way I understand it, most of these HO alternators put out the higher juice at high RPM but mostly have the same low rpm/idle output. So, for our uses they often aren't really any help. Search the board for Boyle Future Technologies and you will find several threads about reconfiguring your OEM alt to provide better output. HTH.

http://www.superpages.com/bp/Auburn-....htm?SRC=local <--all I've got on Boyle

98runner210

I'll try to get pictures of the '04 Alt when I go that route to confirm if it is a true drop in. I am not going to overload the alt. Right now all I have added is drving lights and a subwoofer. I may add heated seats in the future.

ozziesironmanoffroad

put in a GM alternator and be gettin somewhere around 160 amps. lol.

98runner210

I looked but it looked like I would need to cut and splice the pigtail plus it isn't a solid bolt in. Need to fill in gaps with washers and I don't need anything that big with what I plan on running. I am leary of if the 4.7L alt is identical. I hope it is. The 70amp for my '98 is $216.68. I found at the same place the 100amp for an '04 fir $132.00

Noltz

Well keep us posted on this.

Ritzy, that's a very good writeup of the pros and cons of an upgraded alternator. I would only add that if you are upgrading the alternator for additional output (especially those with 160A units) is that your output wire from the alternator post to the battery must be upgraded to handle the increased current. If you power up a winch, with a 160A alternator attached, the field will go full strength in an attempt to keep the battery changed. This extended output may overheat and fry your 'charging' wire, leaving you with a great alternator, but a dead battery.

Edit; Also, for all additional circuts, it's best if you can run a completely separate circuit to power your accessory. Toyota wiring is very reliable if it's not played with. We'll all need to tap into "Power w/key on" type wires... but use them to trip relays & not power accessories.

Reverend

I'm subscribing to this thread. I want to see how this turns out for 98runner210.

98runner210

yeah im waiting to save some $$$ or just go AMEX the damn thing

98runner210

well i pulled a pic of mine VS the V* one and they are different. The V8 has 3 bolting points and they are in different locations and a different plug. damn seemed too goo to be true