LX470 Wrong Alternator Connections Confirmation? (1 Viewer)

[DieGuy]

Car: 2000 RHD LX 470 2UZFE A442F trans

The car has been driving fine since I bought it 6 months ago but theres this parasitic draw of 0.4ish amps which goes away with the "alt-s" fuse
it has led me to the alternator but switching alternator didn't change anything and the wires in between seem to be in good condition. Got me scratching my head major time

However I digging into the electrical diagrams I noticed where my wires are not in the same order as the one I've seen in diagram as shown in the following photos

My alternator connector facing towards you read
1: lamp 2: sense 3: Ignition

But diagram and forums says
1: lamp 2: Ignition 3: Sense

I'm still pretty green in diagnosing electrical stuff like this so I want to ask someone with more experience confirm if this is wired wrong? Or am I mistaken?

 

[AimCOtaco]

That is the normal alternator connector for a 2000 model (1998-2002 really).

If the alternator is related to a measurable parasitic draw then disconnecting the alternator and repeating the test should tell you if it's in the alt or not. My guess is your parasitic draw is elsewhere. When you're measuring the 0.4A you should be able to isolate suspect circuits by removing 1 fuse at a time until you find it.

 

[white_lx]

My alternator connector facing towards you read
1: lamp 2: sense 3: Ignition
But diagram and forums says
1: lamp 2: Ignition 3: Sense

Great trouble shooting, you are correct. According to the above EWD, the order should be 1-2-3 = LA-IG-S (the ones with the 'A' in the circle). Can you double check the wire colors? Those are not visible in your photo. That would allow a quick double-check.

Btw, you circled junction connector EE1 in the diagram, but that has nothing to do with the connector at the alternator. The circles at the alternator symbol represent the 3-pin connector - the ones with the 'A' in the circle. But it looks like you figured that out already.

If S and IG were mixed up, it would make sense to have a parasitic draw as you would backfeed the 'IG' circuit from the battery through the 'S' wire. The connector seems to have a 'strange' color. I have only seen gray and black for alternator connectors. Maybe it was replaced (they fall apart from the heat) and pinned it back wrong order?

 

[DieGuy]

That is the normal alternator connector for a 2000 model (1998-2002 really).

If the alternator is related to a measurable parasitic draw then disconnecting the alternator and repeating the test should tell you if it's in the alt or not. My guess is your parasitic draw is elsewhere. When you're measuring the 0.4A you should be able to isolate suspect circuits by removing 1 fuse at a time until you find it.

Ah sorry mate, I probably wasn't clear enough in the opening thread.

The alternator connector is indeed correct for the model and I have pulled all the fuses and relays. And the findings is that the "Alt-s" fuse is the only fuse that made the parasitic draw disappear when pulled. 2 different alternators have been tested with the same 0.4 amp draw. So maybe the problems the wire/connector. Tested the wires for resistence, all good there.

Then I found that the wires are potentially mixed up in the connector itself which I deduced cross referencing from electrical diagrams.

But I'm not fluent in the auto electric lingo area so I just wanted to double check with the smarter folks to make sure I'm not dumb.

 

[DieGuy]

Great trouble shooting, you are correct. According to the above EWD, the order should be 1-2-3 = LA-IG-S (the ones with the 'A' in the circle). Can you double check the wire colors? Those are not visible in your photo. That would allow a quick double-check.

Btw, you circled junction connector EE1 in the diagram, but that has nothing to do with the connector at the alternator. The circles at the alternator symbol represent the 3-pin connector - the ones with the 'A' in the circle. But it looks like you figured that out already.

If S and IG were mixed up, it would make sense to have a parasitic draw as you would backfeed the 'IG' circuit from the battery through the 'S' wire. The connector seems to have a 'strange' color. I have only seen gray and black for alternator connectors. Maybe it was replaced (they fall apart from the heat) and pinned it back wrong order?

Ah yea, Sorry about the EE1 confusion. That was a little highlight when I was working on the car days before to figure where is what. It does have some relevance for this situation thought as I was using it to test which wire is which. for example I ran a continuity test between EE1 and G2 connector which says
EE1: 1 = G2: 3 - Maybe Wrong
EE1: 2 = G2: 1 - Correct
EE1: 3 = G2: 2 - Maybe Wrong.

Heres a photo of the wires that you have mentioned

They are definately not the black - red - white that the diagram mentioned. So I believe you're right if you're thinking the previous owner may have splice his own connector on old wires as opposed to moving over the terminal pins. will be peeling back the black tape tomorrow for the reveal.

 

[AimCOtaco]

I indeed misunderstood. I think you're on the right track, great job troubleshooting so far. My own notes show the 'S' as the outer, not center pin like you've found. This is one way the alt could be miss-wired to be always "on" but still sensing and working correctly with the engine running... and would result in the draw. Silly luck, great find.

 

[DieGuy]

Just coming back for an update.

So yea it seems someone back then has wired this connector all silly...

It is indeed in fact spliced from the oem wires to an "ebay" prewired connector. with the Ignition(Blue) and sense(Yellow) wires mixed up.
Somehow has the car Starts, go, stop and charge all normal so the last person who worked on this probably thought they did everything good.

I'm gonna may as well replace and redo all the connection since I'm here.
Hopefully that fixes the draw.

 

[David310]

Here is the oval alternator connector for early 100s. Later models had a square connector.

 

[DieGuy]

Heres a final update from me for this issue.

Got a new connector. Chop off the old stuff. Soldered and heatshrink some new wires on them. The colors dont 100% match, the original white is now green but it's alright.
Tested everything I could test. No more Draw. Charging normally, and the alternator is shutting off normally.
All is well now.

Thanks to the folks on the forum who took the time to help. They definitely gave me confidence in my decision.

And for folks in the future who have similar parasitic draw problems where they can't pin point which component is Failing and nothing makes sense.
Search up relevant diagrams and check for Human Error.
I don't know how much auto electric charge for diagnostics but I'll be pretty bummed if I had to pay 200+ for a wire mix up.

This is my first thread on the forum but I hope it's contributable at being helpful for someone.

 

[nissanh]

The middle wire is the ignition and once 12V is supplied to the ignition, the regulator will send approx. 11.6 V to the brush kit. One brush will always be connected to battery via B+ post, the regulator grounds the other brush. Since you had S wire to ignition pin. The regulator was sending full 11.6V to the armeture which heats up by taking 0.4A. A thermal camera is also ideal to locate parasitic draws.