I could use some advice regarding an alternator that won't charge. (I've got a TL;DR down there if you don't feel like reading much)


My battery gave up on me in April. I bought a brand new one. Shortly thereafter, I broke my main belt, boiled the bajeezus out of my coolant system, blew 2 hoses and a core plug, and proceeded to spend the next 2 months dropping the engine, replacing all of the coolant lines and vacuum lines, and putting the engine back in.

Independence from the shackles of a properly functioning charge system:

Last weekend was a 3 day weekend for me. I got home from work Thursday night, parked my car, and proceeded to party hardy for the weekend. Monday morning, my battery was dead. I didn't leave my headlights on or anything like that. The only culprit that I could summon was a Belkin Bluetooth Reciever plugged into an always-on cig lighter. So, I stole my wife's car and went to work.


Monday evening, I called AAA, and they sent out a battery tech. He gave me a jump, and proceeded to test my battery and whatnot. Battery is doing good, but there were inconsistencies with the charge system. He also mentioned how ludicrous my Belkin theory was. He recommended I pop over to AutoZone to get a charge system test done.


The lovely folks at AutoZone informed me that my alternator was dead (diode is good, but the voltage regulator was toast). So, I capped off my long Monday with an alternator removal.

Tuesday, I snatched my wife's car again, and brought the alternator with me. I cut work early and headed to an alternator refurbisher guy (My engine is an RB20DET. As far as I can tell, you can't buy a direct swap alternator here in the states, so I figured I'd get it rebuilt). The guy quick-like tested my alternator (on one of those neat belt-driver machines), and told me that I had an immaculately functioning alternator.


So, back home, I put the alternator back into my car. It's at this point that I found that I had missed one of the wires that went to the alternator plug. I had cut it when I dropped the engine, and forgot to hook it up. Lo and behold, I had also missed a ground strap (god I'm a noob). So, I soldered up the wire that I had cut, reattached the ground strap, hooked all of my belts and whatnot back up, fired her up, and read 13.5-14V at the battery. Huzzah!

There's got to be a morning after:

This morning (Wednesday), my car was dead again. This evening, I busted out the jumper cables and went to town. Here's what I found.


TL;DR My Findings:

1) My car is not charging. With the jumpers hooked up and both cars running, I have 13ish Volts at the battery. As soon as I take one of the jumpers off, the voltage hits 12, and immediately starts plummeting. Starved for electricity, my car dies after about 1 minute.


2) My alternator is wired up correctly. You'll have to trust me on this.

3) My alternator is grounded to the block. Continuity between the housing and the block is good.


4) My alternator is grounded to the chassis. Continuity

5) The chassis is grounded to the battery negative terminal. Continuity

6) My alternator 75 Amp fuse is not blown

7) The alternator pulley spins smoothly and easily. I had to pull a few bolts to get the belt back off, but I did, and the turning action seems fine.


8) The alternator belt has tension, and turns the pulley. Played the most dangerous game, in which you try to gently poke the pulley while the car is running. Yep, it's turning.

9) The alternator, as a whole, is not hot after running for a few minutes. Somebody somewhere on the internet mentioned that some issues cause the alternator to get physically hot. Not the case here.


And I think that's it. I haven't tested the hot side of the connection, because, frankly, it's more difficult than testing the negative side, especially since the car won't run on its own accord for more than a minute.

My current ideas:

1) Test voltage at plug while running. Difficult AND dangerous? Sounds like a plan.


2) Test continuity between the plug and the fuse

3) If possible, test continuity between the fuse and the Positive terminal on the battery (It's a long trip, my battery is in the trunk)


4) Take the alternator back out, and have it tested again. Maybe I broke it while I was installing it?!?!??!?

Beyond that, I'm tapped. Anything you guys can think of?

BTW, I get that my parasitic battery drain issue and my alternator-not-charging issue may not be related. It would be quite the coincidence if they weren't though.


Thanks guys :)