Headlight Mod

[Perez]

Because of its unique size & shape, I assume there is not an upgrade to the headlight bulb for even more wattage short of a relay mod that I saw that looks like it just drives more voltage and current to the existing bulb....not a great idea for bulb life.

Anything else?

[Fred]

Because of age and wire size there tends to be less than 12 volts at the head lamp, so the relay mod should not effect  bulb life. There are higher wattage bulbs available, but with the low voltage it might not be as much of an improvement as you would think. also get carried away and you might melt stuff. Or.... you could get one of those trick HID setups.

[Perez]

Any idea what the stock wattage is and where to get a higher wattage bulb?

[Fred]

55/60 I think? Its in the manual. Almost any on line purveyor of motorcycle parts can set you up.

[Perez]

I have a rather basic understanding of electricity.....how does adding a relay incease the volatge sent to the bulb? A relay is nothing more than an electric switch. Apply voltage/current to these terminals and a switch closes.....

[Pat Conlon]

No problem, here read all about it:
http://www.webbikeworld.com/t2/headlight-relay/motorcycle-headlight-relay.htm

Short answer: It's the large wires that you run to your battery which provides the additional voltage to your light.

Cheers!

[Fred]

It doesn't increase the voltage. You are correct in thinking of it as a switch. What the mod does is eliminate the voltage that is lost in the stock wire harness, by running a direct hopefully larger wire from the battery to the headlamp. The relay uses the signal (voltage) from the wire harness to control the new circuit that was created when the new wire was installed from the battery to the headlamp. So all your switches work as they always have without the voltage drops that occur when running through all the original components.

[Pat Conlon]

It doesn't increase the voltage...... What the mod does is eliminate the voltage that is lost in the stock wire harness, by running a direct hopefully larger wire from the battery to the headlamp. 

Uh, yea,.... The net effect of the mod is that you have increased the voltage to your headlamp....

[Perez]

Not to belabor the point, but I was looking at the wiring diagram in the 'modofications' section and it shows TWO relays.
Do I need two relays, or is that second relay and the secondplug shown for a second lamp?

[Fred]

It doesn't increase the voltage...... What the mod does is eliminate the voltage that is lost in the stock wire harness, by running a direct hopefully larger wire from the battery to the headlamp. 

Uh, yea,.... The net effect of the mod is that you have increased the voltage to your headlamp....

Not to split hairs but the mod eliminates a voltage loss, while this means there is effectively increased voltage at the headlamp, it is not more than the 12 volt for which the headlamp was designed, which I took to be a concern from the original post. If I have read more into the question than I should, I humbly apologize and now return to my corner to work on reducing my use of run on sentences.

[Perez]

Can I wire the proposed setup using just 1 relay if I just want to brighten the existing bulb?

[mikeholzer]

Can I wire the proposed setup using just 1 relay if I just want to brighten the existing bulb?

The second relay is for the high beam. Incidentally, the wattage of a standard H4 halogen is 55W low beam/60W high beam. The bulb is available with up to a 100W high beam; a quick Google search provided many vendors with varying wattages available.

[Pat Conlon]

No, you need 2 relays 1) to activate the low beam and 2) to activate the high beam.

[Perez]

I must be having a stroke or something and I just don't realize it.
I have attached the link to the diagram I am refering to in case we are talking about 2 different things.
       [url]http://www.fjowners.com/index.php?topic=2033.0]       http://www.fjowners.com/index.php?topic=2033.0
It is the attached .pdf file called: Headlight Relay Instr FJ.pdf

In the diagram TWO 3-pin headlight connectors are shown......in other words, for TWO bulbs.
I must be missing something in the way of how one is for low beam and one is for high beam.
.....on a H4 HB2 9003 bulb Low and high are all powered through ONE connector!

[Fred]

One is the original connector that you can plug into with spade terminals to fire the relays the other is a new connector the plus to the bulb.