the one with the RM at the end is a re-manufactured unit, I believe.

 

looks like they are both remanufactured... weird

 

Thanks! How can you tell that the second one is also RM?

 

I'm not sure what Alternator compatibility is between different models in 2011, but I'm pretty sure that for my 2011 LX, the numbers are:
Honda Part No.: 31100-RV0-A01
Alternator Assy. (CSJ24) (Denso)
Seems to fit all 2011-2013 Odysseys, 2012-15 pilots, 2012-14 ridgelines
HOLDER ASSEMBLY, BRUSH - HONDA (31105-RAA-A01).
BEARING, REAR GENERATOR - HONDA (31111-PT0-003). ID 15mm, OD 35mm, width 13mm
BEARING, FRONT - HONDA (31112-5X6-J01). SKF 6303-2RSJ
NEW ALTERNATOR VOLTAGE REGULATOR 126600-3650, IN6365
Denso 126600-3650

and from those notes, it seems that they should all be the same between different flavors of Odyssey, but we know how things can be wrong or change over time. I logged that info a couple of years ago by now.

I see the Denso CSJ24 number is consistent between your data and mine. Denso actually makes the alternator of course. Litens makes the alternator pulley (AOD pulley). I don't know if the pulley is different for LX vs. EXXXL, etc., leading to a different Honda number for the full assembly???

Curious - what's wrong with your alternator? I had my alternator pulley fail at around 90k miles, I think, so I replaced that. Now at 110k miles, the alternator seems fine, with good voltage at all times, but I'm getting the charging light intermittently coming on.

 

Curious - what's wrong with your alternator? I had my alternator pulley fail at around 90k miles, I think, so I replaced that. Now at 110k miles, the alternator seems fine, with good voltage at all times, but I'm getting the charging light intermittently coming on.

Hey oldskewel - thanks for the part numbers. I actually ready your helpful posts about the OAD pulley which made me think to pull of the alternator first and just consider a rebuild instead of buying a new one. I have time and plan to buy all my parts from Honda (After I inspect the alternator). I also have my Service manual and they have a section on Alternator overhaul.

As far as why I think it's the alternator...

Few months ago I was getting a low battery message. I pretty much ignored it because everything seemed to work fine. I also read on line that some people were saying it might be a bug or something. I tended to believe it because the car did seem fine . I figured I would wait and see and after a few months of this message sometimes showing and sometimes not I didn't think much of it (Near the end it would show up more than not but would disappear when driving above 60mph) . About a few weeks ago my wife noticed that when idling the car's headlights and interior lights would pulse a little. Not a lot but just enough to think it was odd. Again I didn't think much of it but I knew something was going on. Next thing we started hearing a rattling sound coming from the serpentine belt area. So now I'm thinking some pulley or bearing is starting to go but again didn't think much of it. (I should mention that just last year we had Honda do the timing belt maintenance and I think part of that maintenance they put a new serpentine belt. I need to double check that) So finally last week my wife is driving and she is telling me things like the van is acting "crazy" transmission is working right, lights on the dash seem to be flashing every which way. She made it home and left it running to get me. I get in and see the main display is literally off and things are flashing everywhere.

I turn the car off and go to turn it on again. All the dash lights come on as well as the main display but the car won't turn over. It just clicks so at that point I finally said "yeah I think our alternator is hosed"

My plan is to first so some of troubleshooting with the alternator in there, take it out and inspect based on some Youtubes and the Service Manual. Determine if I can just rebuild it, and if not just buy a new part from HandA parts or HondaParts Now. Hopefully after all this it actually is the alternator lol.... Is there anything else I should replace in this area since I will be working there?

 

Did you measure any voltages? That info would help confirm things.

The multiple lights coming on at the same time is a universal symptom of a failed charging system. Probably alternator, but could be a loose wire.

Other than the case I'm dealing with now (good voltage, charging light on intermittently), where a CHANGE bATT warning has come up in the past, I've found that CHANGE bATT to actually be accurate. First time it happened to me, everything else checked out so I reset things. I think I then swapped batteries with one of my other cars (standard debugging step I always do with electrical issues).The problem went away on my 2011, but about 6 months later, that battery that the Odyssey had warned was bad did actually fail in the other car, which I thought was an impressive prediction by the Odyssey.

So I'm suggesting the battery would be something to consider replacing too, or first, or testing it / swapping it / charging it to confirm things.

BTW, other than a multimeter, I have found that a good battery charger is a pretty valuable tool in dealing with my cars.

 

I will check with the voltmeter today before pulling anything out. I did notice a lot of corrosion on batter terminal just now so will clean that up as well. Hopefully it is just something as simple as that or new battery. I have a trickle charger that I use on my motorcycle which I have used on my cars and it definitely comes in handy. It takes a lot longer to charge but a lot of times I just leave it over night.

 

Great. That charger should be able to get your battery back to 12+V, even if it takes a whole day.

Once that is back to good, and you've confirmed all connections are good, anything you observe from the alternator will be much more meaningful. So with batt+cables good, if you don't measure ~14V at the battery with the engine running, that indicates an alternator problem ... which would not be a surprise given your other symptoms.

But these preceding steps are things you would want to do anyway.

In case you don't know the procedure to reset the battery management system that generates the CHANGE bATT message - you simply pull out the 2P gray connector on the battery negative terminal. Keep it out for 10+ seconds and plug it back in. I think that clears the message and makes the system reset its memory about the battery state (e.g., voltage change over time, rate of charge) from which it decides whether your battery is on its last legs.

 

Thank you. I didn’t know about that 2p connection trick...

... Well I just went out there and did my MM tests. I had about 12.6 V at the battery after the charge over night. I left the leads on and started the car. It dropped to 11.x and even when I revved to 3000 rpm no change. I then stopped the van, pulled the rubber cap covering the post on the alternator, had my wife start the car and rev it to 3000 rpm and measured again. So from the alternator post it is reading 11.x. I guess that verifies that it is the alternator. Going to take it out now using Michael Hernandez's procedure:

Removing Alternator 2011 Honda Odyssey

From there I will take it apart and figure out if I can rebuild or just buy a new one.

 

Sounds like a good plan. You've almost certainly confirmed a problem with the alternator now.

You may find better instructions on here than with that video, although videos are always good to give you a general idea. I may have listed some instructions on here in the past. From memory, the main things are that doing simple things like removing the coolant and PSF reservoirs will be worth the effort, and may be requirements. Also, the service manual says to remove / loosen the AC compressor to get clearance; instead of that, I got the required clearance by removing the drive belt tensioner assembly. I did that since I had already removed it, and I generally prefer to leave things untouched if I can - the AC in this case.

Once the alternator is out, it will be very easy for you to take it apart and do a quick physical and electrical inspection of it. Post pics of the brushes and slip rings if there is doubt. Hopefully your multimeter can test the diodes too. Feel the bearings for smoothness, which is likely to be fine. Also a good time to inspect the motion of the OAD pulley.

 

Sounds like a good plan. You've almost certainly confirmed a problem with the alternator now.

Well finally got the stupid thing out. Took a lot of breaks so I wouldn't get frustrated. That video I posted earlier helped however I will add 2 more things that I did to allow enough clearance. First there is a bracket that holds the tube for the Radiator overflow container, and it is also the same bracket that holds either the power steering or radiator overflow (can't think while I sit hear typing). Anyway I loosened the 10mm nut that holds it in place just enough so that I could position it sideways/upside down. That gave me about a glorius inch of space. The other thing I did with the tensioning pulley is I put my breaker bar with 14mm socket, pushed it forward (as if to loosen the belts) and used bungee cords to hold in place by attaching it to the holes underneath the hood. This gave me a lot of room. I will post a youtube for anyone else trying this.

At this point I think I am just going to spring for a new OEM alternator. I don't want to fool with the rebuild since I need to get this working by this Friday and have other things to do lol.