Alternator troubles.

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Apparently the rectifier plate was my issue and ruined the diodes.

I’m thankful they were able to fix everything. Even got a fresh coat of paint; I hardly recognized it.

Thanks @GA Architect for helping point me in the right direction as far as shops go.
 
Ignore my fuel level LOL.
But I just cranked up. Seemingly got 12v before start up; but this is what it’s reading now on idle @ just over 2k RPM…
IMG_8775.webp
 
Those gauges suck. Amazon or ebay or even local auto parts store have many different kinds of cigarette lighter volt meter USB charger. It will read A few tenths lower than the actual output, but it's better and 40-year-old even inaccurate when new gauges.

 
Spike Strip said:
Those gauges suck. Amazon or ebay or even local auto parts store have many different kinds of cigarette lighter volt meter USB charger. It will read A few tenths lower than the actual output, but it's better and 40-year-old even inaccurate when new gauges.

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Mmmm okay. I’ve heard a bit about the dash gauges being rather “sucky”…I was clinging to the hope that mine weren’t LOL. It probably is reading wrong though, and I’ll take care of it pronto…

I do want to make a passing note; I don’t get any sound when the key is in the ignition. I don’t know what controls that in particular (maybe the charging light relay???) but that may be up for scrutiny too.
 
GojiraFJ60 said:
I do want to make a passing note; I don’t get any sound when the key is in the ignition. I don’t know what controls that in particular (maybe the charging light relay???) but that may be up for scrutiny too.
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Not sure what you mean here. Do you mean you don't get the buzzer when the key is in the ignition and the door is open?
 
I think pre -1984 does not have the buzzer. After that it's just an extra button on the ignition switch, but it may have been replaced with one of the earlier switches which doesn't have the button. Either that or your buzzer is inoperative or disconnected. The buzzer is under one of the the footwell kick panels
 
Spike Strip said:
I think pre -1984 does not have the buzzer. After that it's just an extra button on the ignition switch, but it may have been replaced with one of the earlier switches which doesn't have the button. Either that or your buzzer is inoperative or disconnected. The buzzer is under one of the the footwell kick panels
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10-4. I saw a couple of things disconnected behind both panels when I first took them off; I wasn’t sure what they were for at the time so I didn’t touch ‘em.
It may not even have a buzzer either like you’re suggesting. I did look at YouTube too and saw a few shorts where some people’s FJ60s didn’t have a buzzer either. But I’ll find out.
 
@bhsdriller I also checked voltage at the battery. Roughly 12.5v.

That said, I think the gauge might be reading correctly.

Still gonna buy one of those that I can plug into the cigarette lighter.
 
Spike Strip said:
You're testing with engine running, AC on, lights on, etc. ? Should be between 13.8 -14.5v
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That was with the engine running, lights on, etc. My AC doesn’t appear to be working, so I didn’t turn it on.

I have no idea what could be pulling power if it’s still hovering around 12.5v.
 
@Spike Strip

It COULD be that my battery needs recharging too. As I understand it, a low battery can affect the voltage output…

Outside of that, yeah I have no idea if something’s pulling power, or what it is…
 
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A low battery voltage will trigger the Voltage Regulator to allow the Alternator to put out maximum or higher voltage, up to 14.5ish V.

If testing is being done properly, and you're only getting 12.5v at the battery, something is wrong. Was the Voltage Reg replaced with the rebuild?
 
Spike Strip said:
A low battery voltage will trigger the Voltage Regulator to allow the Alternator to put out maximum or higher voltage, up to 14.5ish V.

If testing is being done properly, and you're only getting 12.5v at the battery, something is wrong. Was the Voltage Reg replaced with the rebuild?
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Got it…so we can probably rule that out.

I told them I had already replaced the VR when I brought it in, so they didn’t have to worry about replacing it. But I’m on the same page with you; something is definitely going on.

Here’s a thing: Can the terminals affect voltage output if they’re not connected properly?
 
Sure, if you're measuring from the battery lugs and the connection from the leads is bad, or the battery cables are in bad shape.

If you haven't already done it, try it with the multimeter probes on the Cable ends and see if it makes a difference.
 
Spike Strip said:
Sure, if you're measuring from the battery lugs and the connection from the leads is bad, or the battery cables are in bad shape.

If you haven't already done it, try it with the multimeter probes on the Cable ends and see if it makes a difference.
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The battery cables themselves look fairly new tbh. But there’s one that doesn’t look like it was crimped at all and just had some electrical tape applied. I’ll actually send a photo of it in the morning.
 
@Spike Strip

Here’s my positive terminal setup.
The single cable on the left is wired to the starter.

The middle one is wired to the fusible link.

The last one on the far right is wired to a separate fuse box that was installed by the previous owner; it was meant to allow for hookups inside of the truck like a refrigerator and such.

The one I want to bring attention to is the one that is hooked to the starter. I’m gonna take this tape off to show what MAY be a problem.

IMG_8782.webp
 
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