What size fuse

[Hot shot]

Got my 18 watt led for the riding mower
Couple questions
Only putting 1 light on it
Not using factory lights
Correct me if I’m wrong. 18 watts divided 12 volts is 1.5 amps. I’m putting an inline fuse in the circuit. Should I go with a 2 or 3 amp fuse
Next question- obviously each factory light has a hot and ground. Can I wire both hots and both grounds to the new light. The paper said the light will work from 10-30 volts
It says to run the ground straight to the battery which I was going to do anyway but I’m using the factory switch so I’m not sure the switch will work if I go straight to the negative on the battery with a separate ground
Need some clarification

 

[mike93lx]

There is no benefit to wiring both hots and grounds to it for just 18 watts.

The ground can go straight to the battery or the chassis. It will not go to the switch.

2 or 3 amp fuses would be fine. If there is a short, either will blow

 

[wyliesdiesels]

You never switch the negative side(there isnt a ground on this system). Always switch the positive side.

 

[Hot shot]

Thanks
Don’t know why I even asked the question about the ground
Too much going on upstairs

 

[mike93lx]

Thanks
Don’t know why I even asked the question about the ground
Too much going on upstairs

Lol, all good. I won't tell anyone

 

[alfredeneuman]

You never switch the negative side(there isnt a ground on this system). Always switch the positive side.

What about car horns? The switch operates a relay when it contacts the negative side

 

[Hot shot]

I think it’s called brain fade
I need to start taking them magnesium pills that my wife takes
A friend of mine I play golf with, he’ll get to playing bad and says I need some focus medicine. I tell him nah you’ve had too many 12 oz cans of swing lube!!

 

[Wrench97]

Splurge and use a 10 amp fuse.

 

[Terry D]

If you are wiring this to the factory light wiring, and disconnecting the lights, how is it fused now and what size is the fuse.

 

[nadogail]

I agree with Wrench, the fuse is to protect the wiring.

 

[Hot shot]

Nah it doesn’t have a fuse in the light circuit. Didn’t come with one
I just wanted to put one in
After further reading instructions they say to use a 5 amp fuse
That should protect the 10 amp switch
Yes I am using the factory light circuit

 

[mikedodge]

What about car horns? The switch operates a relay when it contacts the negative side

Traditional style Interior lights also work that way. Door opens the switch in the door jamb completes the ground.

 

[Jim greengo]

You never switch the negative side(there isnt a ground on this system). Always switch the positive

You never switch the negative side(there isnt a ground on this system). Always switch the positive side.

Bit of a side track,but who else is older than dirt and remembers back in the day when houses also had fuses on neutral side of circuit?

 

[Wrench97]

Almost all computer controlled components in automotive are switched on the negative side.
If there is a short to ground from a wire rubbing through the computer chips don't fry and all that happens is the component turns on.

 

[rburke65]

I used to rewire older houses and I have seen hundreds of house with both sides being fused!

 

[Hot shot]

These are the lights I have. Yitamotor
Only one light on mower
Mounted the light and wired it up yesterday Worked great
Drove mower from garage to the shed where it’s kept with lights on. Pulled in shed and cut mower off before cutting lights off with switch. Don’t ask me why I usually cut lights off first. cut lights back on and 4 of 6 bulbs not working. Can somebody explain why it did that
Checked out circuit, had 12 volts at the lights
Swapped light with other new one. It’s fine
Called Amazon yesterday, they are going to send 2 more. Yesterday they were out of stock
Today showing in stock and $6 cheaper. What the ****!!

 

[Wrench97]

They probably don't like the vibration............................

 

[PCustoms]

Can somebody explain why it did that

Cheap Chinese lights, hit or miss quality.

I had a very similar one bolted to the hood of my old toro in a pinch (realized I had 0 visibility at night clearing driveway). I unplugged the stock lights, crimped a couple spade terminals to the led and ran the wire through the grill.

Just took it off a few weeks ago, after 3 years outside the lens had fogged and the seal was blown.

 

[Terry D]

Bit of a side track,but who else is older than dirt and remembers back in the day when houses also had fuses on neutral side of circuit?

Yep, I used to be a electrician for the City of St. Louis back in the day. Still had some old Frank Adams panels with knife switches, they had the the hots and neutrals fused

 

[Hot shot]

10-4 on the cheap Chinese lights
My yard is bumpy they probably won’t last long

 

[wyliesdiesels]

Almost all computer controlled components in automotive are switched on the negative side.
If there is a short to ground from a wire rubbing through the computer chips don't fry and all that happens is the component turns on.

except this is on a lawn mower not a car

 

[Wrench97]

except this is on a lawn mower not a car

Which has nothing to do with the statement you made.

You never switch the negative side(there isnt a ground on this system). Always switch the positive side.

 

[Showkey]

Mixing vehicle and home wiring nomenclature is problem.
The OP is not off on his terms.
Vehicles today and going 100 years back were either positive or negative ground. Obviously negative ground won out.
Typical terminology like chassis ground, short to ground, ground strap, bad ground are still in use today.

Shop manuals today still use and supply ground distribution schematics.

Lets go to the next step…….green is ground in the home and not current carrying, black has been historically ground in vehicle’s and is current carrying. Obviously each manufacturer can have their own color code system.

 

[wyliesdiesels]

Which has nothing to do with the statement you made.

i was referring to a lawn mower and there isnt an EGC- equipment grounding conductor, aka ground, nor a GEC- grounding electrode conductor, on a 12v lawn mower electrical system. i stand by my statement...