AUX Switches Max Amp Limit

[MtnGX]

What is the deal on the total amp limitations for the 4 AUX circuits? The way I'm reading info in the manual the upper limit is 23A for "Total Current Value". So 23A max when combining amp draw from 4 AUX circuits? So why a 40A circuit? I'm looking at a light bar that alone draws 33A. I called Lexus corporate technical and also talked to local dealership about this. Response was "what does the manual say". Right.

 

[Mike'sGX]

What is the deal on the total amp limitations for the 4 AUX circuits? The way I'm reading info in the manual the upper limit is 23A for "Total Current Value". So 23A max when combining amp draw from 4 AUX circuits? So why a 40A circuit? I'm looking at a light bar that alone draws 33A. I called Lexus corporate technical and also talked to local dealership about this. Response was "what does the manual say". Right.

The best way to get around that is to use an isolation relay connected directly to the battery.

 

[Garauld]

Aux 1 is fed from a 40A fuse, Aux 2 is fed from a separate 20A fuse, Aux 3 is 15A and Aux 4 is 10A. See images below. You may need to use a 50A relay to power the light bar if if keeps blowing the 40A fuse.

 

[MtnGX]

The best way to get around that is to use an isolation relay connected directly to the battery.

Thanks,. Thought about that as that is the typical set up on a higher amp accessory wiring harness. Have a Switch Pro on my 4Runner so there's always a power distribution module option, too.

 

[MtnGX]

Aux 1 is fed from a 40A fuse, Aux 2 is fed from a separate 20A fuse, Aux 3 is 15A and Aux 4 is 10A. See images below. You may need to use a 50A relay to power the light bar if if keeps blowing the 40A fuse.


View attachment 13605


View attachment 13606

Ok. So what is your take on the max amperage

Aux 1 is fed from a 40A fuse, Aux 2 is fed from a separate 20A fuse, Aux 3 is 15A and Aux 4 is 10A. See images below. You may need to use a 50A relay to power the light bar if if keeps blowing the 40A fuse.


View attachment 13605


View attachment 13606

Even if the fuse for the 40A, or modified circuit doesn't blow what is behind the stated 23A limit on the AUX circuits in total? Is this a battery or alternator driven limitation?

 

[Garauld]

So what is your take on the max amperage.

That may be due to the sizing of the fusible linked circuit feeding power to the fusebox.

Is this a battery or alternator driven limitation?

Doubtful - see prior response.

 

[MtnGX]

That may be due to the sizing of the fusible linked circuit feeding power to the fusebox.


Doubtful - see prior response.

Limitation from power feeding to the fuse box makes sense. I may just go the SwitchPro or similar route since I plan to add several more accessories. Discrete from main electrical and a lot of features. AUX switches could be used for lower amp stuff, engine bay lighting, winch lighting, etc. Thanks for your help.

 

[Garauld]

FWIW, I see that the fusebox is supplied thru a 200A fusible link.

 

[chris.gio]

Aux 1 is fed from a 40A fuse, Aux 2 is fed from a separate 20A fuse, Aux 3 is 15A and Aux 4 is 10A. See images below. You may need to use a 50A relay to power the light bar if if keeps blowing the 40A fuse.


View attachment 13605


View attachment 13606

Where is this from? Did you make it or does this mean there are already relays for the aux switches prepared to provide greater power? If yes, that’s weird because the manual states total load (all 4 switches) is really low and already includes ignition load as I recall.

 

[Garauld]

The above schematics show there are indeed relays controlled by the aux. switches. The driver side FB cover shows Aux relays 1-3 locations:

The pass. side FB cover shows Aux relay 4 location: