LED light bar power GC1715

[apps]

Already have factory rear worklight hooked up to aux power wire at rear. Can I splice into it to power 20" light bar also? I would have to add a switch also as the factory light has the switch mounted in the base housing. I did get wiring & relay with the light bar but this would be a lot simpler for now.

 

[George2615]

If the amp draw of the 20" light bar is equal or less than the rear work light then yes, you can use that power source wire. Probably won't be able to use both light on at the same time. If amp draw is more than the work light it will blow the fuse. If the light came with a relay it probably has a pretty good amp draw requiring it to be powered off the battery with separate switch.

 

[WranglerX]

The stock tractor work light is fused at 10 amp (Fuse #9), actual draw may be 2 to 3 amps...... Yes you can use the same power source as incandescent work light..... Only issues may be when incandescent lamp is on with LED light bar on you may exceed amperage draw on 10 amp fuse...

IF LED light bar amperage draw exceeds the 10 amp fuse, I would add inline fuse at battery post (with correct amperage fuse) and run wire from added fuse to switch then to LED light bar....

Dale

 

[def38]

Cannot answer your question unless we know how many amps your 20" light bar draws. Most 20" LED bars consume about 300 watts power minimum. Many draw much more. Therefore, at 12 volts DC, your 300 watt LED bar draws 25 amps minimum, likely well over the capacity of your current work lamp circuit.


I have installed a LED light bar smaller than yours at the top of my ROPS bar for nighttime work and am running a dedicated circuit with a 20 amp fuse and a switch on the instrument panel.


I would run a dedicated circuit for your light bar using the relay you mention. Make sure there is a fuse in the circuit in the correct location to protect against fire on your machine. Also, it is unadvisable to connect the load directly to the battery. Make your power connection at the starter on the unswitched side of the starter solenoid using a ring terminal secured under the nut on the battery cable terminal. Also, use the correct AWG wire size for the load. Finally, I would recommend running the wiring in split loom to preclude damage from heat or abrasion.


Before beginning any electrical work, remove the negative cable from the battery

 

[apps]

Specs state 126 watts, 7.35 amps. Also found out that factory light is on it's own circuit leaving the aux wire available. Not sure but I think aux is rated at 15 amps. Should be ok?

 

[WranglerX]

Auxiliary circuit (available at rear under seat area) is fuse #7 and is a 15 AMP, however it is controlled by ignition switch... IF you want lights on and key off, its not going to happen.... Odd mention in owners manual says capacity is only 70 watts...

But calculations sort of says 15 amp fuse at 13.5 actual volts should support about 200 watts...

Factory work light (provided on ROPS) is on fuse #9 and rated at 10 amp and is always powered...

Dale

 

[strum456]

I have found that you cannot trust the factor specs of these LED light bars - especially the watt ratings. For example, I just installed a "126 watt" Cree light bar on my sxs. That should be about 10 amps 126/12.5v=10

HOWEVER, as measured by my Fluke DMM, that light bar only draws 4.5 amps, at most.

So, before I would get too concerned about overloading circuits or running wires, I'd put a meter on the LB yourself and find out the true draw. I bet it is less than what you're thinking!

 

[W8BYA]

I have found that you cannot trust the factor specs of these LED light bars - especially the watt ratings. For example, I just installed a "126 watt" Cree light bar on my sxs. That should be about 10 amps 126/12.5v=10

HOWEVER, as measured by my Fluke DMM, that light bar only draws 4.5 amps, at most.

So, before I would get too concerned about overloading circuits or running wires, I'd put a meter on the LB yourself and find out the true draw. I bet it is less than what you're thinking!

You are right on the money. The only way to do this properly is to measure the current being drawn by each of the various components in a particular circuit. Just like your experience I recently installed a 75W 12" LED bar and it drew just under 3 amps ! At 12.5 VDC it should be twice that value. Also keep in mind that if you wire your lights such that the engine has to be running then the current consumption may be less by a little bit because the alternator voltage will be around 14 VDC and not 12.5 VDC. Many of these lights contain switch mode power supplies to ensure they can accept a wide range of voltages w/o burning out the LED's.....this can make back of the napkin calculations approximate only. Again, best bet is a simple 10 second DVM test.

 

[def38]

Specs state 126 watts, 7.35 amps. Also found out that factory light is on it's own circuit leaving the aux wire available. Not sure but I think aux is rated at 15 amps. Should be ok?

Divide the watts power consumption by the DC voltage (12.6 VDC at typical open circuit voltage for a fully charged battery). 126 watts/12.6 VDC = 10 amps. Circuit fused at 15 amps will be safe for your lamp if the specs are accurate.

Good advice to measure the actual current draw. The Chinese are not to be trusted.