Upfitter switches wire guage

Recon

Tremor Member
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2006 Dodge Ram 3500
Picked up my Tremor on January 19. Ordered it on November 5. It is my first Ford. My previous truck was a 2006 Dodge Ram 3500 Mega Cab 5.9 Cummins. I got the 7.3 gas. My mechanic recommended I stay away from a diesel because of the way I use it (a lot of short trips). I've been lurking on here for a while. Anyway I would link to put a 12v power point with an Anderson plug by the trailer hitch. Anybody know what the wire gauge is on switches 5 and 6 witch are rated for 40 amps? I plan on getting a factory service manual on CD but it looks like they are not available until March.
 
I was thinking I would probably go with 8 gauge. It would be nice thou to have a continuous run of 8 gauge right from the relay. 14 gauge is kind of thin for a rating of 40 amps in my opinion.
 
I was thinking I would probably go with 8 gauge. It would be nice thou to have a continuous run of 8 gauge right from the relay. 14 gauge is kind of thin for a rating of 40 amps in my opinion.
You need to measure the entire circuit length from the battery to the load and back again, the truck is 21' long, plus routing it, I'd say calculate based on a 50' circuit length which would be a 2 AWG.

12V-AWG.jpg
 
I was thinking I would probably go with 8 gauge. It would be nice thou to have a continuous run of 8 gauge right from the relay. 14 gauge is kind of thin for a rating of 40 amps in my opinion.
Oh I agree 14 is very thin, but when you unbundle those wires and look at them you’ll see, they’re all very thin. Even the ones that are supposedly rated for higher amperage switches #5 & 6.
 
Oh I agree 14 is very thin, but when you unbundle those wires and look at them you’ll see, they’re all very thin. Even the ones that are supposedly rated for higher amperage switches #5 & 6.
Switch #5 and #6 are rated for 40A and are wired with 10 AWG (apparently). This doesn't seem sufficient to me. I should have my truck on Monday weather permitting so I'll get to take a 1st hand look next week.
 
Switch #5 and #6 are rated for 40A and are wired with 10 AWG (apparently). This doesn't seem sufficient to me. I should have my truck on Monday weather permitting so I'll get to take a 1st hand look next week.

?? that’s the skinniest “10 gauge” wire I’ve ever seen. Now I couldn’t remember if they were rated for 30, or 35 amps. I don’t remember seeing that they are rated for 40 amps but maybe that’s for the 2021?

Mines a 2020, it’s been a while since I’ve opened the owners manual so I’ll have to look again. If they are in fact rated for 40 amps I’ll be shocked, and leery all at the same time. Let me know what you find.
 
?? that’s the skinniest “10 gauge” wire I’ve ever seen. Now I couldn’t remember if they were rated for 30, or 35 amps. I don’t remember seeing that they are rated for 40 amps but maybe that’s for the 2021?

Mines a 2020, it’s been a while since I’ve opened the owners manual so I’ll have to look again. If they are in fact rated for 40 amps I’ll be shocked, and leery all at the same time. Let me know what you find.
2017-2021 switches 1-4 are 25A, switches 5-6 are 40A
2019_08_10_15_19_14_19893e308528159ef58d291f79cb8801d598ef93.jpg
 
I might re-wire my switch load feeds to be beefier if possible... I'm not fond of vehicle electrical fires because the manufacturer wants to save a little money.
 
I might re-wire my switch load feeds to be beefier if possible... I'm not fond of vehicle electrical fires because the manufacturer wants to save a little money.
My preference honestly would be to just use the upfitter switches to trigger a relay then wire the relay directly to the battery for the load.
That seems to me to be a safer method to prevent any electrical fires, and would let me use a heavier gauge wire.
 
My preference honestly would be to just use the upfitter switches to trigger a relay then wire the relay directly to the battery for the load.
That seems to me to be a safer method to prevent any electrical fires, and would let me use a heavier gauge wire.
That would be the proper way to do it to make certain it's wired right. (Apparently-unverified) the wire is only 10 AWG from the battery to the 40A fuse. I do not know if the terminal lug would allow a 2 AWG wire (as said before, I do not have my truck yet). I'd derate the fuse to the maximum wire gauge.
 
I'm glad I've found someone else debating this.

Installing my lights, I'm thinking 90W + 90W + 50W + 50W is approx 21 amps? There's no way in hell I would run even one of these 90W lights on a long 16 gauge run much less a bundle of them.

Like was said, we can run a heavier gauge off the light itself, but the load still bottlenecks at the upditter relay lead, and that's no good. Was here to see how others were dealing with this. Seems redundant to run a relay on a relay but I guess that's what we're going to have to do to avoid ripping a warranty electrical system apart.
 
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