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High Idle Switch Add

bruceb58
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bruceb58 Enthusiast

bruceb58

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I ordered my truck and one thing I didn't order was the high idle switch and now I regret that. I did order the 200A alternator. Ideally I would like a high idle when I am charging my trailer lithium batteries through a 50A DC to DC converter.

 

Anyone add one of these to their gasoline powered trucks after the fact?

bruceb58 Enthusiast

bruceb58

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I ordered my truck and one thing I didn't order was the high idle switch and now I regret that. I did order the 200A alternator. Ideally I would like a high idle when I am charging my trailer lithium batteries through a 50A DC to DC converter.

 

Anyone add one of these to their gasoline powered trucks after the fact?

 

One thing I don't know for sure is if this was even allowed as an option on the gas trucks.

sno1 Enthusiast

sno1

Posted
Posted
14 minutes ago, bruceb58 said:

I ordered my truck and one thing I didn't order was the high idle switch and now I regret that. I did order the 200A alternator. Ideally I would like a high idle when I am charging my trailer lithium batteries through a 50A DC to DC converter.

 

Anyone add one of these to their gasoline powered trucks after the fact?

 

One thing I don't know for sure is if this was even allowed as an option on the gas trucks.

It is an option on gas trucks, uses cruise control to set it.  Sorry I have no idea about adding on to truck not ordered with it

Another JR Senior Enthusiast

Another JR

Posted
Posted (edited)

I suspect it’s simply a software setting the dealer can change. It uses existing switches, so nothing to physically add.  The question will be whether they will do it on your trim level, but I don’t remember there being a required trim for that option when I ordered my 2021 with it. 
 

You should be able to run a 50 amp dc to dc charger (drawing 55-60 amps) from the 220 amp alternator at low idle, though. 
 

 

Edited by Another JR
Typo
bruceb58 Enthusiast

bruceb58

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5 hours ago, Another JR said:

I suspect it’s simply a software setting the dealer can change. It uses existing switches, so nothing to physically add.  The question will be whether they will do it on your trim level, but I don’t remember there being a required trim for that option when I ordered my 2021 with it. 
 

You should be able to run a 50 amp dc to dc charger (drawing 55-60 amps) from the 220 amp alternator at low idle, though. 
 

 

Right now I have a 30A DC to DC and replacing with a 50A. Haven't tried it yet.

Another JR Senior Enthusiast

Another JR

Posted
Posted

Does your truck have a 120 VAC inverter and plug?  I don’t know if they all have them but my mid-level SLT has a 400 watt inverter. To verify the capability to supply 60 amps at low idle, plug about a 300 watt load into that inverter to draw 25 amps while your 30 amp dc to dc charger is charging in bulk mode drawing 35 amps. You will be able to hear that the alternator has a good load on it. Put a voltmeter on the truck battery terminals and I’m pretty sure you will see that the voltage stays steady at just under 14 vdc at low idle. 
 

 

Another JR Senior Enthusiast

Another JR

Posted
Posted

While I have said I don’t think you would need a high idle switch due to insufficient alternator output at low idle for a 50 amp charger, if you plan to occasionally or regularly do extended charging of your camper batteries by idling your truck, a high idle switch is a good idea. It’s better for the engine to run at 1200 than at 500 to 600 rpm for extended periods. 

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