Maximum electrical load for rear (cigarette) accessory port

Ed1

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Apr 29, 2024
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I have purchased a 12V tire inflator that plugs into a (cigarette) accessory port. It is a Viair EVC 85P. It states that the current draw is 15A. The instructions state that it should be used with the engine running (so as to not excessively discharge the vehicle's 12V battery). I purchased this model because I was concerned that it is difficult to use the other models that clamp directly to the 12V battery terminals, due to some of the cargo area plastic trim blocking access to one of the battery terminals.

My question is whether the LC's wiring and accessory port can safely handle a 15A current for an extended period (such as reinflating 4 tires after deflating for driving on sand). The inflator's instructions states that most modern vehicles can handle such a current level, but that it should be verified.

Does anyone know, or know where to find out?
 
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I’m just thinking out loud, but the 12v battery is in the cargo area. A 12v port seems like it could be added and look factory. That port could be wired directly to the battery for the inflator only? I also know that Viair sells an adapter that plugs into the 7 pin plug for the trailer to power the inflators.
 
Thanks, @Lineman . Well, there already is a 12V cigarette-style accessory port in the cargo area. I think it's on the side opposite the battery though. Would that already be wired directly to the battery?

I will check on the Viair trailer adapter, but does it plug into the LC 7 pin port inside or outside the vehicle?
 
The adapter would plug outside next to the tow hitch receiver. The 12v outlets inside the vehicle would definitely pass through the fuse block. I have a Viair compressor and to be honest, I wouldn’t feel comfortable using an interior lighter plug to power it. I use the clips directly to the battery. I’m assuming the worst that could happen is that you would pop a fuse if it overloaded the interior 12v plug.
 
Here you go:
 
Wouldn’t the same issue be present if the inflator is connected with an adapter to the trailer 7 pin port? Does the wiring from that port support 15 amps? And does that wiring go through the fuse box?
 
Yes, the trailer plug goes through the fuse box. I think until someone has access to the electrical diagrams, knowing the amperage is unknown. I guess that someone that has a LC now might know if there is a schedule of the fuse locations? Maybe it may be indicated on inside of the fuse cover?
 
Look at your fuse chart..... determine the fuse size and that'll answer your question.

Can you take a picture of the battery terminal in question and post it please.

My plans are to direct wire into the battery with a relay/fuse bank to power my "add-ons"

Thanks in advance.
 
Following as I have a Viair 88P in my Amazon shopping cart. Wish we could just plug into the inverter but I think the draw might be too much.. and it’s tough to find a Viair with both an AC and DC plug.
 
I purchased a

VIAIR 485C​

I have the same one in my Tacoma, quite enough, does a good job on the 2.2 CFM and a 100% duty cycle.
 
@EOD Guy here's the 12V battery in the cargo area wall. I was hoping to avoid dealing with removing the cargo wall door and the red plastic guard (which is attached tightly to the positive battery terminal and tough to pry off) each time reinflating is needed, so I purchased a Viair model that plugs into the accessory port. Still hoping to verify whether the port will support the 15A max current draw of the Viair.
 

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Much thanks for doing this! I have used the cigar plug in type before and the clip on type. The 485 puts them both to shame. On the Tacoma, I fabricated a "4" way air system, that'll air down all 4 tires and reinflate them to the air pressure I want. 33" KO2s from 11 PSI to 32 PSI in a very reasonable time. I have a air quick connect under the hood and at the rear of the bed. Under hood always hot on/off switch and a "key-on" switch on the console.

On the LC, I plan on mounting the Air compressor behind one of the rear trim panels, with a similar switch and quick connect arrangement.
 
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@EOD Guy here's the 12V battery in the cargo area wall. I was hoping to avoid dealing with removing the cargo wall door and the red plastic guard (which is attached tightly to the positive battery terminal and tough to pry off) each time reinflating is needed, so I purchased a Viair model that plugs into the accessory port. Still hoping to verify whether the port will support the 15A max current draw of the Viair.
Maybe a quick hardwire and easily accessible posts?


Or you could cut the plug on the Viair and wire on a quick connect instead of the alligator clips (just won’t be able to use it on another’s battery).


Just bought a Viair 88P so I’ll probably do something similar
 
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I normally run a short length of 6 gage wire from the pos terminal to a resettable 60amp manual circuit breaker. From the breaker to a relay bank, from the relays to accessories. This has worked well for me in the past, the circuit breaker can be switched off with a press of the reset button, thus killing all accessories I have attached. If one of the higher amp accessories (winch) shorts out the circuit breaker will trip, saving the vehicle etc.... if you want the unplug feature, I'd suggest something like this (BTW the 485 is hard wire only)

1717287960514.png


I use them for my jumper cables on the F250, heavy duty and eliminates arching/sparks.

(Edit) If anyone is intrested..... I have one half hard wired to the trucks battery, cut the jumper cables about 12" from one set of clamps. Installed a connector to each half of the jumper cables (so when hooked to each other, normal jumper cables) that way if I jump from my truck to someone else, easy hook up or if I need a jump etc....... or if I loan them to someone, they are normal jumpers etc...
 
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I have purchased a 12V tire inflator that plugs into a (cigarette) accessory port. It is a Viair EVC 85P. It states that the current draw is 15A. The instructions state that it should be used with the engine running (so as to not excessively discharge the vehicle's 12V battery). I purchased this model because I was concerned that it is difficult to use the other models that clamp directly to the 12V battery terminals, due to some of the cargo area plastic trim blocking access to one of the battery terminals.

My question is whether the LC's wiring and accessory port can safely handle a 15A current for an extended period (such as reinflating 4 tires after deflating for driving on sand). The inflator's instructions states that most modern vehicles can handle such a current level, but that it should be verified.

Does anyone know, or know where to find out?
From the owner’s manual:
IMG_4513.jpeg
 
Thanks @Markarian421 . I was about to check the owner’s manual but you beat me to it.

Looks like my choices for the Viair are (1) hard wire a new port directly to the battery, or (2) return the 85P and get an 88P with clamps directly attached to the battery posts.

I’m not really happy with either option.
 
Thanks @Markarian421 . I was about to check the owner’s manual but you beat me to it.

Looks like my choices for the Viair are (1) hard wire a new port directly to the battery, or (2) return the 85P and get an 88P with clamps directly attached to the battery posts.

I’m not really happy with either option.
You could install an additional 12v port with a 20amp inline fuse connected directly to the battery. Just thinking out loud..... in the rear storage bin, battery side might be a good place to install a covered 12v outlet that would be hidden but easily accessible.
 
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More than likely, the trailer plug is 30 amp. Some of the Toyota wiring diagrams I have found show 30 amps on the positive at the 7 pin. But to be 100% sure, either find the correct fuse or confirm it when the shop manuals are made available.
 
Yes @EOD Guy and @Lineman , inside the cargo floor storage area would be a good place for a new port. But I’m not sure I’m competent enough to be able to get under the bin and cargo floor to run a wire with inline fuse all the way to the battery.

If I can verify that the 7 pin trailer port is on a 30 amp fused circuit, it would seem easier to just get the Viair trailer port adapter and use that port.

Wouldn’t you agree?
 
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