Big 3 upgrade questions!!! Help!!

[diesel_s]

SO I have upgraded my alternator in my 01 SPort from a 120 to a 200 but my battery light came on, so i switched out the pulleys because the one on the new alternator was huge. Batt light still on, but the alternator is definitely working. I ran the new wire from alternator to battery, and battery to frame, but as far as the 3rd wire, where does that run too? and do i need to upgrade my battery?!?!?!

 

[PandorasCustoms]

One of the best "Big Three How To" I have found is over at The12Volt.com

But, the answer you are looking for is:

• alternator positive to battery positive
• battery negative to chassis
• engine ground to chassis

Also, unless you are running ALOT of power a battery isn't going to make a huge difference. Most times, the battery is only affected if the alternator doens't have the power to keep the juice running the amps. So, if you got a 200 on there, should be good for 2800 watts of constant before you drop voltage and run power off of the battery.
(Remember, this number includes all lighting, radio, electronics fan, A/C..... whatever needs juice)

Do you have any idea what the Amperage at idle is? Most alternators that get to the "HO" category sometimes have a situation where they have great WOT Amperage, but sort of low idle amperage due to the pulleys and capacitors.

Big batteries really help the most when either your alternator underperforms, or you run your radio alot with the car off or in idle.

Honestly, if your battery light is coming on, it seems like a miswire somewhere along the lines, It may have something to do with the fact that the sensor doesn't understand the bigger alternator. Not 100% positive on how that sensor reads that information.

But, many times, when I was running my 800 watts (and idling) my battery gauge would drop down near ~12 volts (According the guage, never actualy tested it with a meter). Granted, I only had a 95 AMP alternator at the time, but my battery light never came on.

 

[diesel_s]

Ok here's the deal, at idle, the battery gauge drops very low.......I switched the pulleys out on the alternators and that helped a little. I think the sensor may be having alot of trouble understanding the new alternator, or it may not be able to actually handle that large alternator....I do think my battery needs to be changed, it is about 3 or 4 yeards old now and its a stock battery. At idle, when tested the battery was reading 13.5 - 14 volts but inside it looked a lot different when I looked at the dash

 

[PandorasCustoms]

I am not 100% sure, but I think that as long as the battery is above 12volts, the battery light is supposed to stay off. So, it might be a sensor issue. Positive everything is hooked up properly?
Maybe a voltage regulator issue? If the alternator is not generating the proper voltage (dropping off at idle) it might be somthing along those lines.
Do you know if the voltage regulator is internal or external?

Again, I don't know that much about the alternator side of it except for what it is supposed to test at, and if it is bad.

Can anyone else confirm anything here?

 

[diesel_s]

check it out man, the regulator is internal, what i did wrong was buy a 3G alternator instead of a 4g. I have a 2000 XLT that i will be rebuilding soon that will need a 3g but for the time being because I can't return or swap out the product since I modified the back of the alternator for the big 3 alternator to battery hook up, I took the entire alternator harness of off my red truck and grafted it onto my 2001 Sport and the light went right off. Alternator is doing its job, the problem now is, the battery is stock as hell and the stock wiring has no clue as to how it should handle the power coming through it

 

[PandorasCustoms]

Well, 200 AMPS is a little much for factory wiring. As far as I can remember (no data to back this up), Ford uses 4 AWG wiring for factory power and ground wires. It is said that 4 AWG is only rated for 150 amps of current (Hence the reason the highest stock alternator - that I have seen - for the explorer was 120amps).

You can either run a second set of 4 AWG and just tie it along side the pre-existing wires, or you can run some 2 AWG or higher fresh for the vehicle. It will make sure that your pre-existing wire doesn't burn up.


On a positive note, at least you were able to troubleshoot the alternator error.

 

[diesel_s]

I already ran some 0 gauge wire from the alternator to the battery and from the battery negative to the frame. Next step is to run 0 gauge for the engine ground and replace the stock power wires with 0 guage