General question about fuse box wiring diagram (1 Viewer)

[swankstar]

Just wondering what the "1, 2, 3, 4" mean in this diagram. I searched R/B2 on here and didn't come up with anything and read a few pages before and a few pages after in the black magic cookbook I took the screenshot from and can't find anything.

Reasoning for this is I'm looking for a good ignition on hot wire under the hood to activate solenoid for charging battery #2.

Thanks in advance.

 

[mmajsw]

Identifies the pin number in each plug. Useful for testing, etc.

 

[landcrshr]

They correspond to the terminal #'s in the electrical schematic.

 

[george_tlc]

There's a nice signal that is active when the engine is running (alternator is actively pushing out charge current).

Read carefully through my dual battery writeup -> auxiliary battery and winch which includes the location of the wire in the fuse box behind the main battery (1fz). This of course assumes you still have the stock engine/alternator in your 80...

It's nicer to parallel the two batteries AFTER the engine has started and the alternator is charging things, versus before. Another option many use is a smart battery combining relay (activates only when the main battery/alternator has reached a certain voltage).

i.e. if you aux battery is fairly discharged, you don't want it to be in parallel with your starting battery until you have at least successfully started the vehicle. You then need an alternate way to activate that solenoid in case your main battery is discharged and you are trying to use the aux battery to jump start yourself. In my case I use the manual marine switch, in case of the smart battery combining relay they have a separate wire you can run to a 'jump start' switch.

cheers,
george.

 

[swankstar]

There's a nice signal that is active when the engine is running (alternator is actively pushing out charge current).

Read carefully through my dual battery writeup -> auxiliary battery and winch which includes the location of the wire in the fuse box behind the main battery (1fz). This of course assumes you still have the stock engine/alternator in your 80...

It's nicer to parallel the two batteries AFTER the engine has started and the alternator is charging things, versus before. Another option many use is a smart battery combining relay (activates only when the main battery/alternator has reached a certain voltage).

i.e. if you aux battery is fairly discharged, you don't want it to be in parallel with your starting battery until you have at least successfully started the vehicle. You then need an alternate way to activate that solenoid in case your main battery is discharged and you are trying to use the aux battery to jump start yourself. In my case I use the manual marine switch, in case of the smart battery combining relay they have a separate wire you can run to a 'jump start' switch.

cheers,
george.

Awesome write-up, thank you. So you are pulling signal from the "2" side of the "charge" fuse, I will check that out.

 

[swankstar]

There's a nice signal that is active when the engine is running (alternator is actively pushing out charge current).

Read carefully through my dual battery writeup -> auxiliary battery and winch which includes the location of the wire in the fuse box behind the main battery (1fz). This of course assumes you still have the stock engine/alternator in your 80...

Hi George. Just put this all together, and now only have 11.28 volts coming out of the alternator (measured at the charging battery). I am using a stock replacement alternator from oriellys. It has the little adapter 3-wire connection that plugs into the stock harness. Was charging just fine before hooking up to the fused side of that circuit you pointed out. There seems to be POINT 9 (0.9) volts on the fused side of that wire. Does that sound right? I would've expected 12ish??

The dash voltmeter has been in the 3/4 range since replacing the alternator, and now is right at the halfway mark.

I'm stumped, any advice? Thanks.

 

[george_tlc]

Well, who knows what the drive capability of the oreillys alternator is (on the L signal - which is what is driving the light/warning signal via the fuse). Quite possibly it doesn't have the drive strength of the oem alternator (with its built in regulator).

cheers,
george.

 

[swankstar]

Well, who knows what the drive capability of the oreillys alternator is (on the L signal - which is what is driving the light/warning signal via the fuse). Quite possibly it doesn't have the drive strength of the oem alternator (with its built in regulator).

cheers,
george.

Gotcha, but even with everything disconnected it's stuck at that charging level. Guess I'll swap it.

 

[swankstar]

Hey @george_tlc do you happen to know if that charging light circuit acts the same after doing a Sequoia alternator upgrade (on a 1FZ)? Just curious.

 

[george_tlc]

Hey @george_tlc do you happen to know if that charging light circuit acts the same after doing a Sequoia alternator upgrade (on a 1FZ)? Just curious.

I would think it would be similar. It's essentially just the L signal coming out that goes to 12V to turn off the idiot light on the dash (that has the other end of the bulb at 12V). So, with alternator running an 12V coming out of the L and 12V on the other end of the bulb, the bulb is 'off' and of course that L (12V) indicates good and can be used to power a low current relay coil.

Anyhow, really depends on the L drive capability of the alternator...

cheers,
george.

 

[swankstar]

I would think it would be similar. It's essentially just the L signal coming out that goes to 12V to turn off the idiot light on the dash (that has the other end of the bulb at 12V). So, with alternator running an 12V coming out of the L and 12V on the other end of the bulb, the bulb is 'off' and of course that L (12V) indicates good and can be used to power a low current relay coil.

Anyhow, really depends on the L drive capability of the alternator...

cheers,
george.

Makes sense, thanks!