Type of lights:
First of all, I would NOT advise using "fog lights" or "driving lights". These lights can run up into the 50-100 watt range.
Most of the lights that are used on this type of equipment, are in the 35 watt range.
As for the lights, most of them are of the "flood" type, as opposed to a "spot" light.
They come in many styles, but I would go with a light with a rubber housing. They wont rust and will hold up to the vibration of mowing pretty well.
You can get these lights at almost any auto parts store etc.
The lights with the rubber housing will have two wires exiting the light.
Lights with a steel housing will have one wire.
There are two ways to do it.
1 Have the hot wire go directly to the battery.
If this is done, it is possible leave the lights on and kill the battery.
2 Tie into a wire at the ignition switch that is only hot when the key is in the run position.(recommended)
If this is done, the lights will be shut off when you turm the machine off.
Hooking up wires:
You will need to get a switch, wire, inline fuse and connectors.
Also get some type of a wire sheath or loom, to help protect the wires.
(I would use 14-16 awg wire)
Remove the cover that the ignition switch is mounted in, leaving the switch mounted to it. On the back of the switch you will see some letters stamped into the base(next to each wire terminal). Look for a terminal with a letter "s" or "a".
Hook up a volt meter (neg to ground) set on DC VOLTS, and hook up the red lead to each letter ("s" or "a").
When you turn the key to the on position, and you have 12 volts showing on the meter, check to see if it goes to zero with the key in the off position.
When you get the wire that has 12 wolts in the on, and zero in the off, that is the wire that you will use to power your lights.
This will be your path for the hot wire:
Tap into the one at the switch, and run a wire to the inline fuse, then from the fuse go to the light switch, then go fron the light switch to the lights. As for the ground wires from the lights, I would go to the battery vs. to the frame.
Make sure all wires are tied up and out of the way.
It is easier to say than it is to type, so I hope you can get it figured out from here.
I was just wondering if anyone really knows exactly how many watts can be used for accessories such as lights. I am sure that the mowers are not designed to really produce alot more than what they need for spark. Any help would be apreciated (i use a honda 20hp)
I'm not sure about a 20hp Honda, but a Kohler has a 15amp flywheel alternator. That should be just fine for a couple of utility lights. My JD 318 had a 18hp Onan w/ a 15 amp alt. and it powers a three bulb headlight and two taillights and a rear factory fender mounted utility light fine. Then my Dad adds two more utility lights on a bracket up front for snowplowing. Now when you idle it down with all lights on, it triggers the batt. idiot light. Give it a hair more throttle, and it goes out.
Kohler v-Twins all have 15amp flywheel alts.
Kawasaki air cooled have 15amp flywheel alts.
Kawasaki liquid cooled 27hp have a 30amp flywheel alt.
Kawasaki liquid cooled 22& 23? have a 37amp auto type belt driven alt.
Yanmars to the best of my knowledge have 40 amp auto type belt driven alts.
Also, I would watch where you get you juice from when tapping into the key switch. You might burn it out. They aren't made for a load. How about just adding a small automotive relay and get the main juice right from a major 12V source and the switched 12V from the key switch would just activate the relay.