Upfitters and pass through wires

I got a quick question, the upfitters which is on an 11-16. Does it need/require a relay to wire anything up to those? I was under the impression that the relay was there already, built-in behind the dash connected to the upfitters. If they do you have relays are ready, what would happen if you thought it needed one and you would help at one therefore it would have two. And would that make whatever you hook up to them malfunction or burnout/fry electronics?


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The upfitters need nothing more than you to connect the wires to whatever you want powered. The power is there when the switch is turned on.

firefighterroche said:

The upfitters need nothing more than you to connect the wires to whatever you want powered. The power is there when the switch is turned on.

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Right, I I know that, I know they’re there and where to find them. I’m not that new, lol but I went to a different fforum and there was conversation about whether the upfitters do have a relay, whether, whether it doesn’thave a relay whether you need to add another relay with it if it’s going to mess up electrical equipment if you don’t put another relay with it


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The relay is already there on the 11-16. Kinda nice...not like my '06.

That’s what I thought also. So let me ask you a question its kinda off subject but still on subject. I personally hooked up a onboard air compressor and i used a relay under the dash. It worked for a little while and then it just stopped. That’s why I made the post, I wonder if that guy was right, I wonder if I burnt out my compressor motor.


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You can hook up as many relays in series as you want. It will never change the quality of the power going to the piece of equipment. That is not the issue. It is likely that the relay for your compressor is bad, but a relay is nothing more than an electric switch that lets you use a low amperage switch (upfitter) to run a high amperage load ( compressor). So long as your relay and wiring are sized right all should be fine.


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no need to overthink it. whatever accessory you want to run, just get power from the upfitter wire and ground to either the battery or an OEM post that already has harness grounds running to it. Only thing you have to do is make sure the load of your accessory doesnt exceed the amerage rating of that particular upfitter circuit.

You would add an additional relay if the load was greater than the current relay circuit. A compressor is most likely more than 15 amps.


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rrkroll said:

You would add an additional relay if the load was greater than the current relay circuit. A compressor is most likely more than 15 amps.


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Then use the 25a circuit...