Alternator wiring, help!

[b00stedtalon2]

Alright so I went with Megasquirt on my 2g which means I won't be able to use a 2g alternator since Megasquirt cannot control it like a 2g ecu does. This means I have to wire up a 1g alternator. The 2 prong plug is already wired up but I don't know how I should go about wiring the 2 white power wires. Any ideas? Maybe just run them straight to the battery and not fuse them?

 

[silver bullit]

If you run them to the batery you need to fuse them.

 

[b00stedtalon2]

If you run them to the batery you need to fuse them.

Is it possible to run an inline 80amp fuse? Not sure If I have ever seen a holder for those type of fuses. Because I know on a stock 1g both those wires go to a 80 amp fuse. So maybe I would be okay fusing them at 40 each?

 

[wishihadatalon]

Hey Scott, sorry to be off topic but where did you find that info about the alternator? This is news to me and might throw a wrench into a few of my plans.

 

[b00stedtalon2]

Hey Scott, sorry to be off topic but where did you find that info about the alternator? This is news to me and might throw a wrench into a few of my plans.

Well, Matt told me I would need to use the 1g alternator. And I already had knew the 2g ecu controls the alternators voltage unlike a 1g ecu.

 

[steve]

I need to refresh my memory but I think you could still use the 2G alternator with some minor wiring changes.

There are two additional signals on the 2G alternator FR and G. FR is an output and can be ignored. The G terminal is a input to the regulator and largely turns off the alternator when grounded so if you let it float (disconnected) it should work like a 1G alternator.

 

[b00stedtalon2]

I need to refresh my memory but I think you could still use the 2G alternator with some minor wiring changes.

There are two additional signals on the 2G alternator FR and G. FR is an output and can be ignored. The G terminal is a input to the regulator and largely turns off the alternator when grounded so if you let it float (disconnected) it should work like a 1G alternator.

Perfect! I will try this. But I need to know which pins on the harness are "G" and "FR" or maybe the wire colors on them so I know which wire to cut. And I'm guessing the other 2 wires are what the 1g harness have? (1 wire to 12v, 1 wire to ignition switch)

 

[b00stedtalon2]

Hmm, I don't really think a 2g ecu is going to work without it being controlled by the ecu because the ecu controls its voltage output which means there won't be any voltage regulation. It seems like if I used the 2g alty, it would run hard out at max voltage and it will get killed.

The 1g alternator has a built in internal regulator it seems like. If i'm wrong though, please entertain me.

 

[steve]

All the mitsubishi powered DSMs use alternators with internal voltage regulators. Perhaps your confusing the 2GNT where the PCM is also the voltage regulator.

What the 2g turbos have according to the TRM is the ability to drop the output to 12.3v to reduce the load on the engine for emissions. There is no harm in letting a good battery discharge at times rather than bog the engine at low rpms.

It's possible I misunderstand the manuals but I have read then several times. I can't help with the wire colors, I couldn't find that in the FSM when I looked this morning.

 

[b00stedtalon2]

All the mitsubishi powered DSMs use alternators with internal voltage regulators. Perhaps your confusing the 2GNT where the PCM is also the voltage regulator.

What the 2g turbos have according to the TRM is the ability to drop the output to 12.3v to reduce the load on the engine for emissions. There is no harm in letting a good battery discharge at times rather than bog the engine at low rpms.

It's possible I misunderstand the manuals but I have read then several times. I can't help with the wire colors, I couldn't find that in the FSM when I looked this morning.

Ah okay that makes sense. Well, anyways I found out the wire colors and installed up the 2g alternator. I actually just cut both wires, and left the power ones. Car is all good now

Thanks for the info Steve. I can now drive my car further than just my neighborhood!

 

[steve]

Glad I could help out.