How many amps?

[DaktariEd]

I discovered the dash switch for the air compressor is broken.
The ARB compressor says it has a maximum draw of 20 amps at 12 volts.
How many amps should the replacement switch be rated at?
Right at 20 or higher?

:sombrero:

 

[Pskhaat]

Ed, at 20 amps, I would think the switch would control a relay that could then handle that. Does ARB run the full line through the switch? If so, then yes I'd do 20-25 switch, but I think it may make a lot more sense to have a low draw switch trigger a 30 amp relay.

 

[DaveInDenver]

The wiring harness ARB included with my stuff uses a relay for the compressor and the solenoids are switched directly.

 

[goodtimes]

Yea, what Scott said. Most automotive size relays I have used only draw a miniscule amount on the control side.

 

[DaktariEd]

See? That's why I have you guys out there...to keep me from screwing up too bad...
I tracked down the wiring from the compressor.
Sure enough it leads to a relay. The markings on the relay indicate 12 v., 40 amps.
Does that make sense?
The switch is a very flimsy paddle switch, SPST, with a small light wired inside. No way the wiring to this rice-grain sized light would handle 20 amps...

What do you think?

:sombrero:

 

[asteffes]

You can get some nice Hella-brand LED-lighted switches from rallylights.com. They carry tons of Hella stuff.

 

[Pskhaat]

The markings on the relay indicate 12 v., 40 amps.
Does that make sense? The switch is a very flimsy paddle switch, SPST, with a small light wired inside. No way the wiring to this rice-grain sized light would handle 20 amps...

It actually might be able to handle 20 amps fine, but it ain't good practice, and is a lot of draw and extra big wiring to muster. Is the switch itself gone? If not, just change the relay.

If so, may I suggest instead getting an FJ40 emergency flasher switch (paint the front different if you want)? You can wire it up the same way and have a more classy stock Toyota switch to turn on your compressor.

 

[Robthebrit]

Before you use any LED lighted swithces on a rely, make sure there is a protection diode over the coil. If this diode is not there the first time you switch off the rely the back EMF will kill the LED in the switch.

Rob

 

[Pskhaat]

Wonder if the ARB relays are SSRs?

 

[DaktariEd]

It actually might be able to handle 20 amps fine, but it ain't good practice, and is a lot of draw and extra big wiring to muster. Is the switch itself gone? If not, just change the relay.

If so, may I suggest instead getting an FJ40 emergency flasher switch (paint the front different if you want)? You can wire it up the same way and have a more classy stock Toyota switch to turn on your compressor.

The switch must have been knocked loose. It was non-functional on the dash. When I checked behind the dash, the case was open and the "guts" had fallen out. Like I said...pretty flimsy.

So, I'll run by Auto Zone or some such and get a beefier STST toggle to fit the hole. The flasher switch idea is good...I'll consider that too...

:sombrero:

 

[DaveInDenver]

Wonder if the ARB relays are SSRs?

The one ARB included with my compressor isn't solid state, just plain old electromechanical 1 x Form A, 40A relay.