smoking alternator connection

[yaris2010RS]

Okay so ive been having some sort of electrical issue for about a year and a bit now. 2010 Yaris HB

about a year ago my yaris would randomly die. at that time it got tested at the shop and they determined it to be the battery at that time. changed the battery and Car ran fine till a few months ago, battery light would randomly turn on, everything else would work fine but the light would be on, it was too cold for me to address it and then it went away on its own.

a few days ago the car died again. was doing the same thing as before, slowly losing power till the battery was flat. got it home and went over the system and verified the alternator was not putting out any voltage.

what I found was a lot of corrosion on the main connection to the alternator, I touched it and the alternator immediately began putting out voltage to the battery. but a section of the connector started to glow so decided I should take it apart to clean all the corrosion off.

after cleaning the car runs again and appears to be charging but I'm only getting about 13.6-13.8 v at the battery no matter the RPM. also the peg on the alternator is still getting hot and the wire is also getting hot but the battery light is off.

Before replacing the alternator, is there anything else I can do here and test or clean

[tmontague]

can't think of anything else off the top of my head, based on your voltage it seems the alternator is falling behind. Get a cheap oem one from a recycler typically can be found for $50 and then re check voltage

[06YarisRS]

Maybe do a voltage drop test across both the positive and negative sides to see if there is any resistance. Clean both ends of both cables including the posts and contact points at the bottom of the posts. 13.6 to 13.8 volts seems to be typical charging voltage for my Yari. My 08 is in that range as is my 06. I put a new alternator on my 06 a few months ago. My Sedona, on the other hand, produces 14.3 to 14.6 volts when charging, but it is on 'on demand' charging system.

Below is a link on drop testing. I have decreased resistance on both sides by cleaning/sanding terminals and terminal ends. This was an annual maintenance item for me on my Dodge Grand Caravan. I had a lot of extra electronics in the van and a good cleaning of electrical connections, specifically grounds, always improved electrical performance.

http://www.aa1car.com/library/voltage_drop_testing.htm

I will log my voltages through Torque OBD2 on my 08 and report back later. I have no electrical issues with either car at the moment.

EDIT: I was wrong. My voltage fluctuates
between 14.1 and 14.4. Not sure what
I was monitoring before. I'll check my 06
next time I start it up.

[yaris2010RS]

okay so just to update, I ended up pulling the alternator out and the back cap off and cleaning a bit of corrosion on there. now getting 14.1-14.3 and no heat on the "peg". happy with this result. I guess ill have to keep an eye on it incase the alternator is on its way out.

[bronsin]

The alternator on the wifes 05 Camry was replaced a couple months ago when it started smoking. I wonder after reading this post if we could have saved it? :iono:

[BennyLava]

Check all your grounds. Every ground. That has anything at all to do with the ignition/charging system. Could even be a bad battery cable ground.

[dogsridewith]

What would OP's smoking alternator terminal-to-cable-connector connection do to the working parts of the alternator?
--Locally heat up the terminal post and what is touching it.
--Make alternator work full power all the time to maintain desired output voltage to system. (OP's voltage drop measurements suggest this.)

I don't see that either of these effects would have necessarily hurt the alternator...do think I'll double-check that connection.

[yaris2010RS]

What would OP's smoking alternator terminal-to-cable-connector connection do to the working parts of the alternator?
--Locally heat up the terminal post and what is touching it.
--Make alternator work full power all the time to maintain desired output voltage to system. (OP's voltage drop measurements suggest this.)

I don't see that either of these effects would have necessarily hurt the alternator...do think I'll double-check that connection.

so as my update post suggests, I did end up "fixing" it. I wish I had taken better photos but the concern wasn't the main connection on the alternator, but instead the connection inside the alternator to that post. the entire post form the base was getting almost red hot.

I removed the alternator and disassembled the back cap of it (where the regulator and brushes are housed) and found some corrosion. took it all apart, cleaned it up and now getting a healthy voltage.

I have found a junkyard alternator that I have on my bench for the next time it acts up. the heat could have possibly damaged the regulator but in this case it seems fine.