RB25 Alternator Parasitic Draw issue ???

[Flatline1121]

So ive had an issue with my battery dying after a few day. enough to make it hard to turn over. Began testing for draw.

Getting a draw of .267~ off door shut and all that noise. Pulling fuses and relays. No change more than .003.

I get to thinking, where does power flow. battery, then alt. I pull the 2 pin plug off the alt, .001 draw. Perfect. Now, had to build my own lower harness, and wired the larger plug to 12v. Constant it would seem.

Is this correct or should i wire that to switched power? If thats right, is it more than likely the alt is bad, shorting out just a litle somewhere internally?

[USMCgetsome]

I'm positive in saying that internally it is having a problem. If it was wiring it would have been drawing immediately after you disconnected. Although ensure your checking your 12vdc source and grounds to the chasis and and back of the alternator.

[Flatline1121]

For sure the 12v and grounds are all good. Ive been driving the car with no electrical issues besides this, and the field wire not starting the charge (having to rev the car to 2k to force it) figuring the alt was just acting up, but i could live with that.

I double checked my wiring at the ECU/interior plug. I had to hardwire a ton of that because the engine came out of a bare shell with no wiring at all besides necessities to run the car, and it was hacked to s***. I did find that the white wire (bigger wire in the 2 pin at the alt) shows 21 ohm continuity to ground, which i doubt its supposed to do. Also verified that i had the same wire run to 12v ign, not constant. And i verified that its the single wire responsible for my draw.

so the short of it, the alt is the issue because i have all of the wires run with nylon shielding over electrical tape (whole eng harness is like that) and there are no breaks at all to maybe give that wire a small short.

Im gonna relay isolate it from the wiring its getting now just to bandaid the issue until i can upgrade to a quest alt.

Thanks for the input.

[USMCgetsome]

clean up that ground wire! 21 ohm is not a great source. not bad but you should be seeing chasis ground of .03-.05 ohms. Also I myself just layed in my harness. There was a 2 pin plug by the fuse box in the engine bay. I assumed the wire with a terminal went to ground because the other went straight to the lower engine harness. I cleaned up a chassis ground by the bracket that holds in the fuse box. I still haven't applied power yet to confirm is that wire is supposed to go to ground lol. Working on that.

The parasitic draw means something internally in that alternator is making contact. take the alternator off and have it checked at autozone or your local parts store

[Flatline1121]

The wire I metered to ground is a power wire. Shouldnt that circuit show open when not powered?

The 21 ohm to ground I would say was the short showing in my meter. I put some pretty hefty grounds on the chassis to the engine because I know they can be issues, and 0awg for my battery ground in the trunk running to the chassis under the car. Paint removed and all. They read no resistance when I metered then originally.

[USMCgetsome]

your exactly right. or... I could be resistance from a fuse or relay... gotta trace that line bro. But I do agree it should show open

[Flatline1121]

That line goes directly from a fused 12v source by the ecu to the alt.

[USMCgetsome]

pull the fuse and keep tracing backwards. Your leaking voltage from another harness connector somewhere. Take a pic of the fuse and give us a location and i'll do my best to get up a diagram and we'll keep tracing it till we find out where it's coming from.

[Flatline1121]

Thats the thing, there wont be a diagram because I had to make the lower harness myself. Its literally a wire going from the alt to 12v. What may have been happening is that 12v wire(white at alt) may have been feeding ground with the key off, and a short in the alt was drawing off the charge wire through it.

either way, the issue is reolved for the moment. System charges 14.5v and shows a draw of .006 which is no issue.