Aux light circuit over rated?

Chad D.

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2019 B2650 with the 120W circuit wiring tucked up under the rear fender. Just installed 4 new LED lights under my canopy and wired 'em up. Using a relay, I took power from the OEM circuit and switch it with the tail light hot wire. My LEDs come on when the head lights are on.

Each light is 2.2A, for a total of 8.8A load. Ran for ~.56 seconds and popped the 10A fuse. Replaced fuse, and same thing again. For grins, I tried a 15A fuse for a few seconds and it ran great. I pulled that out and put a new 10A in again. I will run a new fused circuit to the battery for power that is more robust. Easy fix.

Not griping, just letting folks know that the circuit is pretty limited. More so than I would have figured. I'm using high quality lights, and am surprised that they pull 15% more than advertised.
 

GreensvilleJay

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I'm not surprised that they blew the fuse. Was the 2.2A the 'spec' or the actual current drawn? There's a lot of 'lousy numbers' when it comes to 'specs'. Did you run #12 wire to the LEDs?
 
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DustyRusty

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2019 B2650 with the 120W circuit wiring tucked up under the rear fender. Just installed 4 new LED lights under my canopy and wired 'em up. Using a relay, I took power from the OEM circuit and switch it with the tail light hot wire. My LEDs come on when the head lights are on.

Each light is 2.2A, for a total of 8.8A load. Ran for ~.56 seconds and popped the 10A fuse. Replaced fuse, and same thing again. For grins, I tried a 15A fuse for a few seconds and it ran great. I pulled that out and put a new 10A in again. I will run a new fused circuit to the battery for power that is more robust. Easy fix.

Not griping, just letting folks know that the circuit is pretty limited. More so than I would have figured. I'm using high quality lights, and am surprised that they pull 15% more than advertised.
I would check your numbers again. Also, check to see if the headlights and taillights are also on that same circuit.
 

Chad D.

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I would check your numbers again. Also, check to see if the headlights and taillights are also on that same circuit.
Agreed that the label shows 120w, which is likely right where my mod is. 120w at 8.8A is 13.63V. That would make sense, but I’m still a bit surprised that the 10A fuse was blowing with a presumed 8.8A load. To be honest, I was a little surprised that the circuit rating is as close to the actual capacity as it is! Regardless, it won’t be an issue in the future!

And, the headlights are on a separate circuit. From what I can tell, that 10A circuit is only for the auxiliary lights. The only relationship the headlights have with my setup is that they energize the coil in the relay to turn on my auxiliary lights.
 

Mark_BX25D

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I’m still a bit surprised that the 10A fuse was blowing with a presumed 8.8A load.

Those numbers don't surprise me. That's almost 90% of rated capacity, and that's cutting it too close for comfort.

But as has been said, check it. Those ratings are probably Chinese marketing flim flam.
 
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cthomas

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I also remember a study that GM was forced to do after a number of car fires from one dealership franchise and they found the parts dept. got some harbor freight(ish) type of fuses that the 15 amp fuse would not blow until 58 amps was applied. Tech would look at vehicle found blown fuse, replace fuse, did not blow, and issue resolved. Until later when the harness went up in flames. Of course then I remember my grandparents house and the whole house was on 4 screw in type fuses.
 
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Chad D.

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Those numbers don't surprise me. That's almost 90% of rated capacity, and that's cutting it too close for comfort.

But as has been said, check it. Those ratings are probably Chinese marketing flim flam.
Ah, no Chinese marketing flim flam with good ol’ US made Baja Designs lights! Lol. They’re made in San Diego.
 
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Chad D.

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I also remember a study that GM was forced to do after a number of car fires from one dealership franchise and they found the parts dept. got some harbor freight(ish) type of fuses that the 15 amp fuse would not blow until 58 amps was applied. Tech would look at vehicle found blown fuse, replace fuse, did not blow, and issue resolved. Until later when the harness went up in flames. Of course then I remember my grandparents house and the whole house was on 4 screw in type fuses.
That’s pretty scary!!! Yikes!
 

Pawnee

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A fuse is a blunt instrument.
It is meant to protect downstream wiring from burning by sacrifice.
In general, you can load a fuse to 80% of its rating, so your 10A fuse will hold 8A "forever".
As the amperage is increased, the fuse will hold for less time but in a non linear way.

It will hold 10A for say a minute, and 100A for a micro second.
The above is just for illustration, for real numbers you can look at some fuse (time x current) graphs.

Same applies to circuit breakers.
 
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Runs With Scissors

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Running at ~90%, I'm not too surprised that it popped either.

I wired some shop lights last year in my pole barn and I'm at about 85% on that circuit, and it don't take much to pop that breaker. Its basically a dedicated "lights only" circuit now.

Paul
 
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Runs With Scissors

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Of course then I remember my grandparents house and the whole house was on 4 screw in type fuses.

Yep..... and my grandpa would shove tin foil in there when he didn't have a spare fuse.....Now that's Old School for ya......🔥 hahahah.....LOL
 
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ve9aa

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Curious. On my relatively new BX2380 it's a 20A fused circuit
(13.8V x 20A = 276W) and I power lots of LED lights with it.
1679660334490.png



I don't have a manual for a "B" close by but I am wondering why Kubota would do that.
 

555

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Hello if its any help I just finished putting a Kubota 3rd function on my B2601. When I tested it it immediately blew the fuse. I checked the fuse box up beside the motor and found Kubota put a 5 amp fuse in, so I checked the service manual and it says "up to 35amp Max. Changed to 10 amp. ok so far.
 
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ve9aa

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2019 B2650 with the 120W circuit wiring tucked up under the rear fender. Just installed 4 new LED lights under my canopy and wired 'em up. Using a relay, I took power from the OEM circuit and switch it with the tail light hot wire. My LEDs come on when the head lights are on.

Each light is 2.2A, for a total of 8.8A load. Ran for ~.56 seconds and popped the 10A fuse. Replaced fuse, and same thing again. For grins, I tried a 15A fuse for a few seconds and it ran great. I pulled that out and put a new 10A in again. I will run a new fused circuit to the battery for power that is more robust. Easy fix.

Not griping, just letting folks know that the circuit is pretty limited. More so than I would have figured. I'm using high quality lights, and am surprised that they pull 15% more than advertised.
further to my last - I just yanked this off the net. Should be for your tractor.
Are you tapped into the correct wire?
1679661309298.png
 

Chad D.

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further to my last - I just yanked this off the net. Should be for your tractor.
Are you tapped into the correct wire?
View attachment 98715

Having a tough time deciphering these diagrams, but I’m relatively certain I’m on the right circuit. It’s been pretty well documented, on this site and others, that the unused power leads under the right rear fender (photo attached) are typically used for auxiliary lights. It’s just not as capable as I would have thought.
 

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ve9aa

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Having a tough time deciphering these diagrams, but I’m relatively certain I’m on the right circuit. It’s been pretty well documented, on this site and others, that the unused power leads under the right rear fender (photo attached) are typically used for auxiliary lights. It’s just not as capable as I would have thought.
I'm not here to argue with you, so don't get the wrong idea from me but the B2650 manual (and my BX manual--no, not exactly the same tractor) are both rated to 20A. (so more than double the wire you're showing the picture of)

Is there even a remote chance you have the wrong wire and that's for something else? (on my BX I think it was under the left rear fender--yes, not the same machine)..and iirc, there was no tag on it, just a bullet connector. A couple years ago I had to trace the wire to insure it was going to the correct 20A fuse in the fuse block.

(If I had a B2650 I'd tell you what color wire to look for-but there must be a schematic out there or other B2650 owners than can verify what color wire)

Good luck Chad
 

Chad D.

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Sep 21, 2019
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I'm not here to argue with you, so don't get the wrong idea from me but the B2650 manual (and my BX manual--no, not exactly the same tractor) are both rated to 20A. (so more than double the wire you're showing the picture of)

Is there even a remote chance you have the wrong wire and that's for something else? (on my BX I think it was under the left rear fender--yes, not the same machine)..and iirc, there was no tag on it, just a bullet connector. A couple years ago I had to trace the wire to insure it was going to the correct 20A fuse in the fuse block.

(If I had a B2650 I'd tell you what color wire to look for-but there must be a schematic out there or other B2650 owners than can verify what color wire)

Good luck Chad
Apologies if I came across argumentative. I didn’t take your post negatively, and didn’t intend to respond poorly!

There is definitely a chance I got the wrong circuit when I put it together! If so, I bet a lot of others have as well. Would love to hear more if there is a 20A circuit available. That would be plenty and eliminate the need to add a new circuit.
We’re on our way to Italy today and I’ll be back to check this next week! It’s not going anywhere till then!
 

jimh406

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I think it should only be used for a relay. Run other wires to the battery to provide the power.