# What gauge wire for CAT lights ?



## 02powerstroke (Nov 7, 2006)

What gauge wire for CAT lights should I use and what amp relay.


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## Yooper75 (Dec 30, 2010)

I would say a 12g or 14g wire would be sufficient for those lights.


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## Yooper75 (Dec 30, 2010)

You will want a continuos use 20amp relay as well.


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## newhere (Oct 13, 2009)

Yooper can you explain why a relay is needed? I always ran my ground to the frame and then I ran the hot lead into one side of the cab mounted switch out the other side into a fuse and then to the battery. Is my way inferior?


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## Too Stroked (Jan 1, 2010)

When you start switching something (lights in this case) with a large amperage draw, if you simple run all that amperage through a switch, you tend to fry the switch do to arcing pretty quickly. What a relay does is separate the load into high and low amperage draw portions. You use the low amp draw side to energize a coil that then does the actual high draw switching. This also allows you to take the high draw side directly from something proper (like the battery) and the low draw side from something convenient (like a fuse panel). 

So I guess the short answer is that if you use a relay in high current draw situations, you'll find that you have a much safer and more reliable circuit. Hope that helps.


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## swtiih (Nov 30, 2008)

Using a relay is definetly a good idea. 14 gauge wire is good for 15amps , 12 guage wire is good for 20amps. Stranded wire is what you want to use not solid. I would personally use #12.


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## 02powerstroke (Nov 7, 2006)

I'm going to run 12 to them from the relay but the wire on the plugs is only 14 but I'm going to have them wired together so it will be a combined load.


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## 2COR517 (Oct 23, 2008)

What is the amp draw/wattage rating of the lights? How are you switching them? How many are you using?


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## basher (Nov 13, 2004)

02powerstroke said:


> I'm going to run 12 to them from the relay but the wire on the plugs is only 14 but I'm going to have them wired together so it will be a combined load.






2COR517;1179074 said:


> What is the amp draw/wattage rating of the lights?


Definite need to know.


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## 02powerstroke (Nov 7, 2006)

basher;1179077 said:


> why is that a no no? the wire coming out of the lights it only 14 gauge. I ran 12-2 trailer brake wire back to the 40 amp constant duty solenoid, I'm switching it with a toggle switch that activates the solenoid.


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## 02powerstroke (Nov 7, 2006)

12V 3"X3" H-3 flood 12v 55w 4 amp $25.11


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## RBRONKEMA GHTFD (Dec 17, 2006)

You might want to use 2 relays. Maybe even 3. And divide them between the relays, Thats a lot of amp draw for 1 relay.

If I were wiring this project I would get 2 or 3 relays. I would power each relay with a 10 gauge wire fused with 20 to 25 amps These connections would be made at the battery. Then I would run a 14 gauge wire to a bussman 6 fuse fuseblock. Each relay would have its own designated fuse block. I would then wire each light into the fuse blocks however I or the customer would want them switched. I would then get a good ground off a seat bolt and using 1 10 gauge wire. (If I have to wire a lot of lights and want 1 common ground I will bolt the wire to the seat bolt then bolt the other end to a L bracket and use a longer bolt with double nut on it. Make sence?) I then would run 14 gauge wire to 2 or 3 switchs for triggering the relays. The switches can be wired to a key hot just like your plow so they are only on when the key is on. I would run a 14 gauge to power the switches also. I would also fuse that feed wire with a 10 to 15 amp fuse. Also the grounds for the relays would be 14 gauge. If you like I can make a harness for you with all the stuff I listed above here. Pm me if you need more help and or would like me to make a harness. If so everything would be in a box so nothing is loose. Look at my box I made http://www.plowsite.com/showthread.php?t=109569&highlight=my+ebling. page 2 post 32. It loos like a mess but that pic was taken when I was wiring everything.


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## basher (Nov 13, 2004)

12 X 4=48, so you need a minimum 48 amp switch capacity. Plus some heavy wire if you are doing them in series. Even if you relay them you need to consider a winch relay or similar 60 plus rated relay. 

I would wire them in groups of four using a 20 amp relay for each group. Using relays would allow running light gage wire into the cab cheaper and easier to do. You could also use a lighted switch with a reasonable price. Having the lights divided into groups allows you to save power when all the lights are not needed. Amp hour storage is critical in most equipment as so much depends on it.


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## 02powerstroke (Nov 7, 2006)

it says they draw 4 amps each so thats 8 amps cause I have to lights whats the big problem here????


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## 02powerstroke (Nov 7, 2006)

Grounding off a seat bolt is a dumb idea I had a truck light on fire because of that.


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## 02powerstroke (Nov 7, 2006)

RBRONKEMA GHTFD;1179335 said:


> You might want to use 2 relays. Maybe even 3. And divide them between the relays, Thats a lot of amp draw for 1 relay.
> 
> If I were wiring this project I would get 2 or 3 relays. I would power each relay with a 10 gauge wire fused with 20 to 25 amps These connections would be made at the battery. Then I would run a 14 gauge wire to a bussman 6 fuse fuseblock. Each relay would have its own designated fuse block. I would then wire each light into the fuse blocks however I or the customer would want them switched. I would then get a good ground off a seat bolt and using 1 10 gauge wire. (If I have to wire a lot of lights and want 1 common ground I will bolt the wire to the seat bolt then bolt the other end to a L bracket and use a longer bolt with double nut on it. Make sence?) I then would run 14 gauge wire to 2 or 3 switchs for triggering the relays. The switches can be wired to a key hot just like your plow so they are only on when the key is on. I would run a 14 gauge to power the switches also. I would also fuse that feed wire with a 10 to 15 amp fuse. Also the grounds for the relays would be 14 gauge. If you like I can make a harness for you with all the stuff I listed above here. Pm me if you need more help and or would like me to make a harness. If so everything would be in a box so nothing is loose. Look at my box I made http://www.plowsite.com/showthread.php?t=109569&highlight=my+ebling. page 2 post 32. It loos like a mess but that pic was taken when I was wiring everything.


dude I'm wiring two small work lights? they are fused at the battery and the switch power is fused as well,


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## 2COR517 (Oct 23, 2008)

I think somewhere along the line people got the impression you were installing 12 lights......


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## 02powerstroke (Nov 7, 2006)

2COR517;1179381 said:


> I think somewhere along the line people got the impression you were installing 12 lights......


lol that would be ********....


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## RBRONKEMA GHTFD (Dec 17, 2006)

02powerstroke;1179375 said:


> dude I'm wiring two small work lights? they are fused at the battery and the switch power is fused as well,


Sorry bud, I miss read it. I thought you said you were wiring 12 cat work lights. That's why I wrote that up.


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## RBRONKEMA GHTFD (Dec 17, 2006)

2COR517;1179381 said:


> I think somewhere along the line people got the impression you were installing 12 lights......


I will be first to admit it.


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## 02powerstroke (Nov 7, 2006)

RBRONKEMA GHTFD;1179428 said:


> Sorry bud, I miss read it. I thought you said you were wiring 12 cat work lights. That's why I wrote that up.


No problem the write up was a good one if I were using that many lights lol


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## EGLC (Nov 8, 2007)

02powerstroke;1178513 said:


> *I'm going to run 12 to them from the relay but the wire* on the plugs is only 14 but I'm going to have them wired together so it will be a combined load.


this is where me and others got confused  Thumbs Up


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## Dissociative (Feb 28, 2007)

geeeze...i thought i had bright lights.....why you doing 12 lights?.....hehehe


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