Alternator, fuse or rely??

Morning folks, I have an 09 Tacoma TRD sport. I was camping and had been using the outlet(truck was off just had the key turned) in the bed to run a pump to inflate some floaties at the lake. The pumped stopped working and I didn't think much of it because it does over heat. Next time I started the car my battery light was on. I was fairly remote and had to drive out on a 4x4 track. Made it half way home and lost all power and had to be towed. Currently charging the battery and expected it to be the alternator that went. Only upons researching what alternators I can replace it with I discovered my truck has two models 100w or 130w both require a different fuse. So got me thinking could I have tripped something electrical?

I have looked at most fuses but haven't noticed and burned but how do you check a relay?

Has this happened to anyone else and do you have and recommendations?


Thanks.

 

You will want to check your ALT (120A Without Tow Package, 140A With Tow Package), ALT-S (7.5A), and IG1 No2 (10A) fuses, there are no relays in the charging system.
Also should check for power on both White wires and the Green wire at the alternator, if all that checks out you most likely have a bad alternator.

 

I have checked all but the IG1 no2, both the other were fine by the look of it. I couldn't take the 140a out Buti popped the little plastic cover off and nothing was burnt or broken.

I'll che k the IG1 now.

 

IG1 no2 is intact

 

The cover you popped is not meant to be removed.
Use a multimeter to verify fuses that "look" fine.
The 120A is bolted to the internal busbar of the relay/fuse box.

 

Thanks, going to borrow multi meter now.

Will updates results.

 

If you check the big wire at the post of the alternator with a test light your effectively checking the 120/140A fuse so no need to tear the fuse bix apart if it's good.

 

Battery ring terminal to alternator wire.

 

I mean if you have power at the charge post of the alternator with the truck off the fuse is good, no need to go any further. Not that you can't check it at the fuse box, it just seems like extra work but everyone has their own testing methods so...

 

I didn’t see where you said if charging the battery and trying to start the truck worked?

Maybe I missed it.

Just mentioning this, as maybe you are over thinking it and it really is the alternator and nothing else?

 

All fuses are reading 0.03 ohms so I'm assuming they're all good?

Battery is reading 12.65v when the truck is both on and off.

 

Man, I might have missed it.
But what exactly is the problem?
Is the problem that you think the alternator isn’t charging?

Does the truck start?
When you say ON, does that mean running?

 

In the original description above I was using the inverter outlet to fill up some floaties and then the pump died and the next time I turned my truck on the battery light was on I was able to drive out of the backcountry area I was in and made it halfway home before I lost all power battery was completely drained. I just recharged the battery and reconnected it trying to figure out if it's the alternator that's gone or if there was some fuse that was blown because of the pump and inverter

 

Yes the truck turns on yes it stays on but the battery isn't being recharged while it's on and my battery light is on on the dash

 

Sounds like the Alternator.
When you used the pump at the rear outlet, it likely drained the battery low.
But not low enough to to not start the truck.

Alternators don’t alway charge, they turn on and off.
When the battery is low, the alternator probably stayed running longer than normal.
This isn’t bad, and it’s normal. But it’s like anything else, it gets old and tired.
And the extended charge time probably finished it off.
It isn’t your fault, it’s just part of normal wear and tear.

I mean you can test the alternator, but you need a meter that can check up to 30A DC to check it right.
Or do like most people and just check voltage. Which is basically what you’ve done, and confirmed by NOT seeing 13v+ when the truck is running.

https://www.purefjcruiser.com/docs/2007 Toyota FJ Cruiser Repair Manual/1GR-FE Charging/Charging System/01500.pdf

 

OP, ALT-S fuse (7.5A) is verified?

 

Yes. Intact. 0.03ohms

I changed all fuses out with spares just to make sure. No change in situation.

 

Sounds like you’re going to be pulling the alternator.
It’s not a particularly hard job. Most auto parts stores can test them.
The hard part will getting a good reliable alternator from a parts store.
I’d probably spend the money and get a factory reman or new if you can find one.

 

https://www.mechman.com/alternators/toyota/tacoma/4-0l/2005-2010/