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Alternator wiring

22K views 22 replies 2 participants last post by  buffv1 
#1 ·
Hi,

Upgraded my stereo yet again, have some 0 and 2 AWG cables left and was thinking about upgrading wiring from alternator and battery.

Question is:

1. Can i reuse the original connectors or do i have to get new? Which will i need?

2. Was thinking about 0 AWG from battery negative to chassis
Alternator to battery positive 0AWG
Engine to chassis ground 0AWG

Any thing else? It's an MY06 2.0 NA, i think alternator is std issue here in Norway 110Amps.

Was searching forum, but didn't find any info.
 
#2 ·
Ok let me clarify some more.

Alternator is Mitsubishi 23700 AA521 A3TG0491 5X05. It is either 100 or 110A.
Dealer said it was 110A, but it's most likely 100A.

1. I will run 0 AWG from Alternator + to battery +, with a fuse, question 1 how big fuse do i need. 100A? or less.
Mounting on the alternator is 8mm, i think, is that correct

2. I will run 0 AWG from Alternator ground to Engine ground. Do any one have any pictures og good grounding spot there? How is the mounting?

3. I will run 0 AWG from Battery - to chassis (strut housing) and i think that is 10mm.

Do i need to do anything else? Engine to transmission, if so there are those connection.

I live far from any autoshops, and i have to order most stuff to be delivered. Thats why I have all those questions.

Reason for "upgrade" is that i upgraded my audio system and now my lights are dimming than i crank up the volume :shrug: I have 0 AWG going from battery to fuse/distribution block and 2 AWG to amps from there.

Thx in advance
 
#4 · (Edited)
Yeah, got 2 actually.

0,8F and 1,3F mounted close to each amp. approx 20 cm

for RF T400.2 and T600.2
Same happening without capasitors. I thought at first it was caused by them (during charge)

I only have like 8 awg from battery to ground, so i think this may cause it. So i'm planning on doing big 3 upgrade. Will it help?

Rgds
 
#5 ·
It sounds like you need major power, so your only option may be to install a higher output alternator & the largest capacity battery that you can fit in your Forester.

Of course cleaning all the connections & adding additional grounding couldn't hurt.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 
#9 ·
No real problems if you're just adding more grounding, but before you start removing & rerouting the 12V power (alternator to battery), I'd suggest you get the wiring diagram, so you know how the existing 12V power is routed.

As to the fusing of the alternator. Unlike the battery, even if you increase the wire size from the alternator, it can only provide the power it's rated at. If the alternator is rated at 100A, that's all you're going to get out of that alternator. As to the fuse, check fuse SBF-1 in the engine compartment fuse box. On my '07 FSXT it's a 120A fuse.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 
#10 · (Edited)
Ok,

Got a new alternator from Maniac HO 160 AMP, but now a have a different problem.

Then i'm running new ALT output is only 14.05-14.2, My CEL is on and CRUISE is blinking. ODB returns error P2503.
But everything works without any problems (14.05 is lowest with EVERYTHING on). I did not add any extra wiring except extra grounding.

With my old alternator which is actually 110AMP, I read constrant 14.4-14.5, no CEL. But as soon as i turn everything on (light, fans,seat heaters, stereo) It drops to 13.2, no CEL or anything, but my lights dim and start flickering.

Than i changed alternator i did the following
1. disconect bat -
2. disconnect bat +
3. disconnected alt controll plug (3 pin on the alternator)
4. disconected powerwire from alt
5. changed alternator
6. powerwire on
7. controll plug
8. bat +
9. bat -

Did I do something wrong?



Any tips before I go to stealership? Or before i put in old alt?


PS. I tried resetting codes, but they return after 5-10 seconds.
 
#12 ·
Did you buy the Maniac HO 160 AMP alternator new? If so, I'd also run your problem past them.

Looking over their website, they say you need to run a new cable, 4 gauge (or better), between battery + & alternator charge post is needed as an additional path for current to the battery. They also recommend a 100A in-line fuse.

Any chance you removed the old alternator wiring? From what I'm reading, the old wiring stays.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 
#13 ·
Old wiring is still in place. I haven't added new. But i will try and do it in couple of days time, since I didn't have a "small" fuse holder :D

I'll report back then I tried it out.

Just a quick question regarding ODB2, im using ScanXL. When do you reset CEL errors? While engine is running og when ignition is on (just before starting engine mark)?

Cause I'm not able to read any data until engine is started.

Rgrds
 
#15 ·
Old wiring is still in place. I haven't added new. But i will try and do it in couple of days time, since I didn't have a "small" fuse holder :D

I'll report back then I tried it out.
If you're running the old wiring, my guess would be that it should be working. From what I read, the extra wiring was to provide an additional current path to the battery under heavy load.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 
#14 ·
It may be different in your Country, but here in the States, but my Scan Tool will connect to the ECM with the key in the run position without having the engine running... the position just before start or crank.

You can reset CEL when the engine is running, but normally you want reset the CEL before you start the engine. After the CEL is cleared, turn the key to run, but don't start. This gives the ECM time to boot properly after a reset.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 
#16 ·
That was the same impression i have. Original wiring looks to be around 4AWG (2 wires)

I will try with added path later this week.
But:

1. Could it be that i have "to much" ground ? I have added 0AWG wire to Chassis, and replaced engine to transmission with thick grounding strip, instead o the old thin cable

2. Could the alternator belt be to "slack"? But i should have heard screaming noise from the belt

3. If there was not enough voltage, my battery should have drained after the use i had with stereo and lights/blower/heated seats.?

4. Or does ODBII with ScanXL unable to read the code correctly, as far as could read from different forums that software is not 100% compatible with Subaru. But it still does reset ECU.

Could that be that voltage regulator on the new alternator doesn't "talk" to my ECU? Or should that also have resulted in drained battery than just the CEL? I tripple checked that 3 pin connector plenty of times and it is securely connected.

Thx for your input sofar.
 
#17 ·
On the control plug for the alternator. The one here in the States only uses 2 wires on the 3 pin plug. Are the new & old alternator plugs the same, as in the wires being in the same place?

The drive belt for the power steering & the alternator should be pretty tight. If it deflects too much when pressed with your thumb, you need to tighten it up a bit.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]
 
#18 ·
Belt is pretty tight. Connector is the same as before original to my car. 3 pins. On the new alternator the plug for the connector was also 3 pins.

Ill check with maniac if the alt i got support for 3 controll wires, or if its made for usdm models only.
 
#19 ·
If your alternator plug has 3 wires, that may be the problem. As I wrote, here in the States, the alternator control cable has a 3 pin plug, but only has 2 wires are connected.

Bobby...
Here's how my alternator control plug looks. Note there are only 2 wire on the plug.

['07 FSXT Member Journal] ['03 X Member Journal]
 
#20 · (Edited)
Yeah i know.
Here's a pic of "norwegian" connector it's for MY06 2.0X


I have put in the old alt, and cleared the fault.
Until i get an answer from Maniac i'll wait with upgrading to new alt.

From what i found out so far 3'rd wire is volt sens, and if that's true it corresponds pretty good with error i get from ECU.
 
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