Fuse box fried...

[isis]

The 80% part is the manual saying to not run a constant current larger than 80% of the maximum for the switch. Likely for low voltage and surge and whatnot. But yes if you stay within those limits you’ll just screw up your light and not the whole truck.

 

[isis]

So in your example if someone were using an upfitter switch rated at 20 amps, but running an 8 amp load. This person should swap the 20 amp fuse for a 10amp fuse?

It wouldn’t be the worst idea if you didn’t use an in-line one somewhere.

 

[Jakenbake]

Kind of, it's very long winded, but basically don't rely on just your wiring to be sized correctly, it needs to be protected properly with a fuse, that's the most important thing to grasp from this conversation.

I’m on board,and in the case of the upfitters they are a fused circuit are they not? I am running an Eaton RTMR with 5 relays for most of my items, but I am also using the the factory upfitters for a few items too. I am below 80% for each of the 4 switches but this brings me back to why 80% and thus our conversations.

The 80% part is the manual saying to not run a constant current larger than 80% of the maximum for the switch. Likely for low voltage and surge and whatnot. But yes if you stay within those limits you’ll just screw up your light and not the whole truck.

So based on that info should I lower the fuse for the upfitter circuit to better match the load and by doing this I am saving my light rather than the truck?

 

[isis]

I’m on board,and in the case of the upfitters they are a fused circuit are they not? I am running an Eaton RTMR with 5 relays for most of my items, but I am also using the the factory upfitters for a few items too. I am below 80% for each of the 4 switches but this brings me back to why 80% and thus our conversations.



So based on that info should I lower the fuse for the upfitter circuit to better match the load and by doing this I am saving my light rather than the truck?

The original rating saves the truck. The fuse sorted for the load saves both.

Just curious, what’s an Eaton RTMR?
Edit. Nevermind. I googled it. We make that in Oregon or Juarez. Pretty neat gizmo.

 

[Jakenbake]

It wouldn’t be the worst idea if you didn’t use an in

So in my gen 1 I am running

Switch 1 (fused at 30 amps): 2 XL 80's ( 80W/12V=6.67amps -> x2 = 13.34amps) 44.5% utilized
Switch 2 (fused at 30 amps): Icom F5021 (Current drain roughly at 10 amps per manufacturer) but radio has its own fuse so this circuit should be fine
Switch 3 (Fused at 15 amps): 2 S2's (can't remember pro or sport -> 24W/12V=2amps -> x2 =4amps) 27%.....
Switch 4 (fused at 10 amps): trigger wire for ARB air compressor relay, so I am not sure what it is actually pulling but the manual calls for a fuse of at least 8 amps.

 

[isis]

So in my gen 1 I am running

Switch 1 (fused at 30 amps): 2 XL 80's ( 80W/12V=6.67amps -> x2 = 13.34amps) 44.5% utilized
Switch 2 (fused at 30 amps): Icom F5021 (Current drain roughly at 10 amps per manufacturer) but radio has its own fuse so this circuit should be fine
Switch 3 (Fused at 15 amps): 2 S2's (can't remember pro or sport -> 24W/12V=2amps -> x2 =4amps) 27%.....
Switch 4 (fused at 10 amps): trigger wire for ARB air compressor relay, so I am not sure what it is actually pulling but the manual calls for a fuse of at least 8 amps.

Reducing your fuse ratings will protect your loads without independent fuses. Most decent LEDs have over voltage protection so maybe it’s not a thing. But the trucks switch fuses are for the wiring. If your load will be damaged before that kind of current is reached a different fuse will help protect.


A compressor is an electric motor and will pull a bunch of current at startup so make sure you look for that inrush current level that @CoronaRaptor mentioned. You need a lot of headroom on a motor fuse. Unless the trigger wire means it’s a relay. But that’s a hell of a lot of current for a relay.

 

[sixshooter_45]

I’m on board,and in the case of the upfitters they are a fused circuit are they not?

Yes the switches are fused as follows:



1st switch = BD 30" light bar = 180W or 15A/15A =1 or 100% load of rated fuse amperage so I'll be adding a relay to handle the current.

2nd switch = a pair of BD XL80's = 11.58A/15A= .77 or 77% load of rated fuse amperage.

3rd switch = a pair of BD Squadron Pro Spots = 6.66A/10A = .67 or 67% load of rated fuse
amperage.

4th switch = a pair of BD Squadron Pro Driving/Combo = 6.66A/10A = .67 or 67% load of rated fuse amperage.

5th switch = a pair of Baja Designs Squadron SAE Wide Cornering = 3.2A/5A = .64 or 64% load of rated fuse amperage.

6th switch = a pair of BD S2 Pro = 3.32A/5A =.66 or 66% load of rated fuse amperage.

I believe this will work using existing switches except for switch one which will, as stated, require an additional relay.

If I've stated something incorrectly, let me know.

 

[Jakenbake]

Reducing your fuse ratings will protect your loads without independent fuses. Most decent LEDs have over voltage protection so maybe it’s not a thing. But the trucks switch fuses are for the wiring. If your load will be damaged before that kind of current is reached a different fuse will help protect.


A compressor is an electric motor and will pull a bunch of current at startup so make sure you look for that inrush current level that @CoronaRaptor mentioned. You need a lot of headroom on a motor fuse. Unless the trigger wire means it’s a relay. But that’s a hell of a lot of current for a relay.

I may temporarily reduce the fuses in the up-fitters for piece of mind, but I am eventually going to switch to a switch pro's set up so I will have to look how that system is fused/setup.

Yes, switch 4 is for the trigger fuse for the relay(s) on the compressor. There might be two relays since it is the ARB twin. Yes I have a home run running from the battery back to the bed fused at 80 amps for the compressor.

 

[Jakenbake]

Yes the switchesare fused as follows:

View attachment 157669

I'm a gen 1, but good info for the gen 2 crowd.

 

[isis]

I may temporarily reduce the fuses in the up-fitters for piece of mind, but I am eventually going to switch to a switch pro's set up so I will have to look how that system is fused/setup.

Yes, switch 4 is for the trigger fuse for the relay(s) on the compressor. There might be two relays since it is the ARB twin. Yes I have a home run running from the battery back to the bed fused at 80 amps for the compressor.

Makes sense. Relays are inductive and have a bunch of surge for on and off events so maybe they are just oversized. Whatever the manufacturer says to fuse the load at is what you should use.