If alternator dies, will AHC go with it? (1 Viewer)

[MongooseGA]

Hey all,

I've done some searching but didn't find much. Feel free to link a thread if one already exists on this matter.

Quick back story: My LX (235k miles) had been making some pretty ugly whining noises under the hood. Flicking the lights on and off changed the pitch, and my PS fluid was flushed 2x while the noise persisted, so I'm thinking it's likely that my alternator was on the way out. Assuming what I was hearing was the bearing noise I've read about.

Last weekend I took her out to the N GA Blue Ridge for the day. Did some pretty easy trails, mostly in Neutral position, including a couple of romps through a door-seal depth mud hole.

After a thorough pressure washing the next day I noticed that the battery light was on solid on the dash and now my AHC isn't functioning. Bearing whine is now gone, leading me to believe the alternator is now completely toast. Voltage on the cluster only shows barely over 9V and my multi-meter on the battery posts while running shows 11.8V. I left it in LOW as I'd planned on a long paint correction process (I'm not as tall as the car unfortunately), so it's currently stuck there, bouncing off the bump stops over bumps. The light in the AHC position indicator just flashes next to whichever position I select, and the pump is not audible at all (duh, it's not running). I've only driven it out of the garage and around the block since parking it.

New alternator arrives tomorrow. I'm hoping someone here might have some good news that my AHC pump is just not getting enough electrical power to run it. Reservoir is still full, I have not noticed any leaks in an otherwise still well-functioning system.

Thoughts?


Pic for attention and proof that Lexus' get dirty, too.
Dropbox - 20180304_155150_HDR.jpg

 

[planomateo]

If I had to guess, I'd say yes, from what I see in the electrical wiring diagram, there are 3 fuses - 50A, 15A, and 20A.

Our Honda Odyssey just had an alternator failure about a week ago, ABS, VSA systems failed as well. I just replaced the alternator this morning...what a pain as there isn't enough room to get the damn thing out easily.

 

[MongooseGA]

If I had to guess, I'd say yes, from what I see in the electrical wiring diagram, there are 3 fuses - 50A, 15A, and 20A.

Our Honda Odyssey just had an alternator failure about a week ago, ABS, VSA systems failed as well. I just replaced the alternator this morning...what a pain as there isn't enough room to get the damn thing out easily.

I see the big blue fuse in the box under the hood. Is there a trick to getting it out without taking out every other one next to it? I can't get anything in there to release the clips to pull it out and test it.

I don't love alternators. This will only be the 3rd one I've done (though, probably the 5th time I'll have R&R'd... yeah, that sucked). I plan to take my time and just get it done. From what I've read it shouldn't be too nasty. I imagine a hell of a lot easier than the one on my '85 diesel Benz, which was caked in so much oil gunk I couldn't see the bolts!

Have a listen to this bad boy!

Dropbox - 20180304_151024.mp4

 

[flintknapper]

You might check the condition of your battery while you are at it.

Replacing the alternator on these isn't 'horrible' but its pretty tight down there. Toyota chose to put the starter way up high (under the intake manifold) but then put the alternator at about the lowest point on the engine, so they catch a lot of rain, dust, dirt, debris.

Some folks take them out from the top...but I have found it MUCH easier to sneak it out through the bottom.

There are plenty of threads on it. Just use the search function.

I'd recommend that you have a new connector on hand before you start. Chances are good yours will be brittle and break when disconnecting.

 

[MongooseGA]

Great info about the connector. Think it's something local parts stores might have handy? I know the dealer will be closed for parts tomorrow.

Battery is new within about 6 months or so. I do imagine my alternator housing looks a lot like the one in the pic though! Does anyone ever use a sort of cover to keep so much solid crud from getting in there? (Besides abstinence, we all know that never works )

The R&R isn't so much a concern. I'm really just hoping it's related to the AHC. That'll be a lot pricier and more involved than just the electrical juice box.

 

[PADDO]

There’s an input to the AHC ECU (REG) from the alternator that tells the ECU the vehicle is running. If that signal is missing or below threshold then the system doesn’t know the engine is running and the AHC/AVS is effectively disabled. There is a chance you’ve creek water or pressure washing moisture where it shouldn’t be too, but you need a properly functioning alternator for the system to work as designed.

 

[MongooseGA]

Well, fxxx me...

Picked up the new alternator yesterday. Got to the point of buttoning everything back together and cross threaded the damn bolt on the bottom of the alternator.

I took the nut and bolt to my local hardware store, no matches. Called the dealer first thing this morning, they don't have it in stock and won't until tomorrow morning. I am stuck on a bike until I can get this one wrapped up or the parts for my OTHER daily driver get in later this week.

Does anyone know what the dimensions and thread pitch are for the bolt that secures the alternator?For bonus cool points, anyone in metro ATL have some spares they'd sell today? I'd even consider a tap and die kit to straighten out the bolt I have now.

Ugh..

 

[Hokie LX]

FWIW,

My AHC functioned fine right before my alternator died.

If you were pressure washing the underside, you may have gotten some water in one of the height sensors. When a sensor fails, it can lock up your ahc and cause the flashing light when you try to adjust height.

My truck recently did the flashing light thing when my rear sensor failed. Replaced it and all is well again.

 

[MongooseGA]

Well,

I managed to get the original bolt to work. I cleaned up the threads, lubed the orifice with some PBB to keep it from getting hot and sheering, and just worked it back and forth. At the end there was about 1/4" that would not thread with out significant force and sheering would have caused me to throw my radiator across the garage. What I did was use a big nut (heheh) as a thick washer so the bolt could tighten down and squeeze the alternator to the mountain surface.

Success! The whine is gone (thank god), the gauge shows 12+V, and my AHC is functional! It may be psychosomatic but I feel like it even cycles a little more quickly and smoothly.

I had the old (original, 235kmi) alternator bench tested, it was putting out 8.5V


Also, I noticed not many (or any) of the DIYs mentioned removing the radiator and fan for this job. Honestly, for the extra hour of work, I found it was paramount to not getting fed up with the tight spaces in this job. That, and re-routing the serpentine was so much easier than having to work it around the fan.

 

[MongooseGA]

Quick update:

The first evening driving around was great. On my commute home the next day, I had an intermittent battery light on the dash when I would hit the brakes or the lights turned on. I figured loose connection somewhere. By the time I got home, I couldn't reproduce it again so I left it.

Last night a guy at a drive-through window made a comment about a burning smell. Get home, sure enough the plastic cap over the ground cable (I assume?) on the alternator has been melting. Easier than a belt smoking, but still not awesome.

I'm planning on crawling back under today to scrape the cap off and check the cable. Besides just not being connected properly, would anything else be causing this? FWIW, the alternator is one of the 100A models, up from the 80A I believe it came with.

 

[MongooseGA]

Here's the carnage:

https://photos.app.goo.gl/RmcJejPG17LTlxl82

 

[MongooseGA]

And my solution: https://photos.app.goo.gl/Gq7NucFACGhZceHv1

When I was removing the 10mm nut from the threaded post, the post sheered off inside the nut (lovely).

Luckily there was enough of the threaded post left to still tighten the lead down to it. I took the lower nut off, spread the wings on the connector and tightened it down that way. I didn't notice or smell any more burning so I imagine it's fine, albeit I'm sure not what Toyota would have done.

If this is a stupid solution, please let me know! I'm completely ignorant when it comes to electrical. I can do suspension and engine work no problem, but have never figured out electrics. The whole system still works just fine. I'm wondering if maybe it had not been adequately tightened before. Thoughts?