Charging system input?

[EvanD]

Hi guys,

97 LX450 with 280K owner here.

I feel like crap coming and asking for advice since I'm not a regular contributor (mostly I just learn here)...but I'm stuck.

A couple weeks ago my voltage meter dropped as I was driving. The truck ended up dying. I replaced the battery (it was around 4 years old) and hoped that was the issue.

It wasn't. Or at least not all of it. As I drove the 20 minutes home and the battery didn't charge above 9 volts or so according to the dashboard meter. In the following couple of days it charged to normal strength for the first 5-10 minutes of driving and then could go back to hovering around 9. It's not totally dying so there is (I assume) some charging going on.

I have a fair amount of accessories (aftermarket stereo, winch, bull bar lights, etc) so I have a lot of terminal connections. I cleaned them all up and replaced a bunch. The issue is still going on. Sometimes. For about 2 hours of driving between yesterday and today it had no issues.

I've had it tested at Napa, O'Reillys, and Autozone at this point. Napa and O'Reillys said it was fine (that's when it was working). Autozone said it was only running around 12V (that's when the light was back on today).

The belts seem fine and I can't notice and alternator bearing whining. Still, I bought an alternator and new belts today. It seems like the next step. I'd have to go back through all the previous owners service records to know when any of these items were changed.

Also, when it works, it works. There isn't any variance in whether I'm on the gas or not. When it doesn't work, same thing. It just hovers around 9V.

Does anyone disagree with changing the alternator and belts or have any other ideas of things to check first? I've searched pretty extensively and can't find much else on input of what to do.

Thanks in advance!

-Evan

 

[Cruzerman]

Seems like you've ruled out cabling and battery. That leads me to think about the alternator. I would get it tested before I just replaced it. I typically will get mine rebuilt by the local shop rather than get a cheaply rebuilt unit from the auto store. But that's just me.

 

[morganism]

Don't those have a seperate voltage regulator?

 

[inkpot]

Don't those have a seperate voltage regulator?

Internal

 

[inkpot]

Have you checked/replaced your disable links? $15 ish

 

[EvanD]

Cruzerman,

Sort of. The battery is brand new so I'm comfortable saying that isn't the issue. I haven't totally ruled out the cables. All I've done is fix the terminal ends. If there's an issue on the other ends I haven't gotten there yet. I did buy an alternator (rebuilt) at Auto Zone today but didn't even attempt to install it. I was hoping to get some input here before I went down that road. I may return it and get one off of Rockauto anyway. Auto Zone had me pay something like $50 bucks more than places like Rockauto. I'm definitely not against paying the money for any part of this process and I have a trusted local shop. It just seems like something I should be able to do easily enough myself.

I've had the alternator tested at Napa, Auto Zone, and O'Reillys. When the system is working/charging properly it tests fine. When it's reading low on voltage and not fully charging it tests as an issue (they say the alternator is only running at 12V or so).

Morganism,

As mentioned, I'm pretty sure they are internal to the alternator. I haven't looked into whether they can be replaced independently but for the relatively low cost I'm inclined to just replace the whole thing if I dig into it.

Inkpot,

I won't lie, I have no idea what disable links are. I'll start poking around that right now.

Thanks all for the input!

-Evan

 

[EvanD]

It may be unrelated but I have been having issues with power windows and the window sprayer for a couple years. They all work but not like they should. I figured the windows were related to dirty trim and the sprayer to some issue in that system but haven't torn into either of them yet. They may be related to a general power issue. At least it sounds that way.

-Evan

 

[EvanD]

Are what you call disable links also called fusible links?

-Evan

 

[flintknapper]

Are what you call disable links also called fusible links?

-Evan

Yes, he meant fusible link. But I doubt that is your problem. Good to always have a spare set on hand though.

 

[EvanD]

Thanks! I'll definitely add it to the box of parts I travel with. I have no idea if it's the actual issue. That's where I ended up with a new alternator and belts. As it seems, I can either mess around with each connection, or just replace the biggest possible issues first and go from there. Ultimately, the alternator and belts are some relatively cheap parts and a 3-6 hours of labor. I know people do it in a lot less time but I'm trying to account for never having done it.

I suppose I just didn't know if anyone has had a similar issue what worked for them.

 

[EvanD]

I suppose I'll add a picture of my rig so this isn't totally a waste for the more knowledgeable people.

 

[Cruiser Ed]

This is just a hunch but it sounds like something is seriously draining your system to get the battery to 9 volts. Maybe the alternator has an internal short.

Nice looking rig by the way.

 

[inkpot]

Are what you call disable links also called fusible links?

-Evan

Yup. I just hate my spell checker!!

 

[EvanD]

Cruiser Ed,

Agreed. The extra weird part is that it's still charging, at least partially, all of the time after the new battery. I figured a new alternator and belts would be the next best course of action after the new battery and terminal connections. I'm headed on a 10 day road trip in July and if I don't do that I'm terrified I'll be missing the mark and/or the problem.

The problem has shown to be super intermittent and seemingly unrelated to any running of power draw. Sometimes I can run high beams, wipers, and the winch and it's fine. Other times I can turn them all off and it still doesn't get above 9V.

And thanks for the compliment. I can't take credit for the build but it came from your neck of the woods in Phoenix.

Inkpot,

Totally agree on the spell check thing! Anyway, I'll absolutely be taking a look at fusible links tomorrow, probably replacing them, and ordering a couple extras to keep on hand. Even if that isn't the cause it seems like it can be a pretty serious area of issue.

 

[Dave 2000]

Intermittent voltage regulator, bad connections, fan belts worn, they can be bow string tight but worn out so not grip the pulley correctly.

Regards

Dave

 

[flintknapper]

^^^^^^ Intermittent voltage regulator makes the most sense to me.

 

[Cruzerman]

Seems to me that if you've taken the alternator out and while being tested it showed sometimes good and sometimes bad, then your alternator is flaky. I think these are internally regulated, so it could be the voltage regulator. I'd get it rebuilt by a local shop.

 

[EvanD]

Cruzerman,

It's only been tested while in the vehicle. By 3 different auto parts stores but I'm not super confident in any of the people that tested it.

All,

Thank you very much for the input. It's going into a trusted, local shop on Thursday. After spending way to much time researching and being sold the wrong belts by Autozone I'm just going to saddle up and pay some coin. I've never looked as closely at my engine bay as I have over the last couple days but now that I've learned more about the electrical side of things...well, there are a lot of red flags. Basically, a bunch of connections (some cut off and some with their female ends) that don't lead anywhere (nor do they look like they ever did). I've never really had electrical issues since I bought the truck in 2014 but this is way above my knowledge and free time. Plus, I need to trust it. I can't do that if I try to tackle it myself. At least not for way more time than I want to put into it.

-Evan

 

[ZackR]

Cruzerman,

It's only been tested while in the vehicle. By 3 different auto parts stores but I'm not super confident in any of the people that tested it.

All,

Thank you very much for the input. It's going into a trusted, local shop on Thursday. After spending way to much time researching and being sold the wrong belts by Autozone I'm just going to saddle up and pay some coin. I've never looked as closely at my engine bay as I have over the last couple days but now that I've learned more about the electrical side of things...well, there are a lot of red flags. Basically, a bunch of connections (some cut off and some with their female ends) that don't lead anywhere (nor do they look like they ever did). I've never really had electrical issues since I bought the truck in 2014 but this is way above my knowledge and free time. Plus, I need to trust it. I can't do that if I try to tackle it myself. At least not for way more time than I want to put into it.

-Evan

Thus far things are pointing to intermittent issues with the alternator. If it were me I'd swap out the alternator and belts.

 

[Tools R Us]

Thus far things are pointing to intermittent issues with the alternator. If it were me I'd swap out the alternator and belts.

Have seen the intermittent thing when the brushes wearout.