Subway4X3 Shameless Copycat Build

I’ll try this.
Hell... I’ll try anything at this point.

 

Did all this start happening after your new alternator? Once you get your ultra gauge in, I would be curious to see what your “ECM Voltage” output is. Mine floats at 14v

 

Ultragauge arrives Wednesday. Yay!!!!

 

New high output 250 amp alternator I installed early February because 11.8v output of my 1 year old original OEM alternator.


This crap started happens last month or so i measured the output at 11.8v, so I asked and they sent me a warranty replacement 250 Amp alternator which was replaced last month. The output is still 11.8 v, so yesterday, I bought and replaced the alternator with a 180 Amp alternator from Advance Auto Parts. Still 11.8 volts.
So, the original and three new alternators at 11.8 volt output on all four.

It’s safe to say that it’s not an alternator issue.

 

Someone suggested that there’s a fuse that’s in the engine bay fuse box that regulates when the alternator starts charging. Anyone familiar with this?

 

There is a wire in the engine bay fuse box that provides the measured voltage for when the battery is charging. There's a reference too it somewhere in the 2nd battery or battery relocation threads. It's one of the wires you tie into when doing a blue-sea ACR install.

 

Now we’re getting somewhere with these NEW investigative leads.

I’ll try to find the reference thread Turin, but if you find it first, I’d love to have a link
to it.

 

https://www.tacomaworld.com/threads...-booster-upgrade.604478/page-37#post-24295984
Its in this thread. Somewhere. The fuse is the "Alt-S" fuse if I remember correctly.

 

Whoever the hell you are. THANK
YOU!!!!!



And welcome to my build page!

 

Haha no prob! Just a west coast thread-stalker here!!
I ordered the replacement fuse rather than the adjustable gizmo after installing an AGM battery.

 

Hi @crashnburn80 !

I know you’re an electrical guru type.

I did your headlight upgrade several years ago.

Maybe you can help me with my voltage regulation issue?

Please see last several posts on this thread.

Thanks!

 

I think its in here somewhere: https://www.tacomaworld.com/threads...batteries-thread.295653/page-93#post-17499851

 

Thanks Turin! I’ll look at this closely when
I get home. I think there is hope.

 

Ok. So I know where the find the WHITE voltage sensing wire at the alternator connector and at the engine fuse box.

What do I do with this wire?

Just check for continuity? Check the fuse where this is attached?

 

Back in the day you changed the pully size....

 

Did you check the Alt-S fuse? Try swapping with one of the spare fuses on the fuse box lid even if it seems fine and recheck your voltage at the battery with the truck running. There shouldn’t be any load on the Alt-S circuit, so swapping the 7.5A with a 10A spare will be fine for the test. I believe the 2nd Gen voltage regulator is integrated into the alternator, meaning it sounds like an issue on the voltage regulator “Alt-S” circuit.

 

TorquePro is cheap and that's what I've been using with the cheap Amazon obd2 plug in

 

Make sure the voltage there is the same as the voltage on your battery. If it's higher at the fuse box than you're not getting as much juice to the battery as you should. If it's the same then the problem is probably the actual sensor/controller.

 

My 10 year old Harbor Freight multimeter crapped out.

Got a decent replacement this time. A Klein Auto Ranging model. I looked at Fluke, but this one had same/more functionality at half the price.

 

oooo link? I have an old OLD fluke and some of the buttons are falling off. I want to replace it.