Very good information to know and have handy.
I have a problem with my headlight's not turning on, so i'm about to re-wire it.

http://www.r1200gs.info/howto/relay.html

 

here's another site that I just ran across.
http://www.ripper1.com/tech/wiring/
This may explain "relay" more and has some very intresting info on other things also.

 

Ever since I bought my 93 CBR couple months ago, I've had problems with the headlight not coming on. I know they work, because I changed the bulb's and they have came on one-time while riding. So for the past couple week's I have been researching and buying part's to rewire my headlight. I could have simply traced the wire that was loose, but I opt to rewire-just for the sake of research and curiosity of how a relay works.

I understand that there are diffrent ways to wire up a relay, but this is the way it work for me.
[IMG]local://upfiles/1672/C14D3F96EBC3473DAF0ABFF591C07809.jpg[/IMG]
Above: This is the commonly used bosch relay- I got the one is rated at 30 amp-these can be found at your local automotive parts store for ~ $6.00. The switch is an on-off-on switch, used for my Low beam, off, and High beam- The yellow wire in the middle is my power wire from the relay # 87 (accessory) dont know if its necessary to add a fuse, but I did-just in case. The switch I got for ~$3.00 and the fuse ~ $5.00.

[IMG]local://upfiles/1672/F540096FC5E64F6A822EBAA3B08CE36E.jpg[/IMG]
Above: Here is the switch and three prong universal headlight plug. The yellow wire powers the switch and gives charge to nothing if on the off position (middle) and power to Hi (in my case up) or Lo (in my case down). The wires for Hi and Lo, goes to my three prong plug.
If you were to look at the prong from the back, in a pyramid shape (single wire at top), the single wire at the top is my low beam, the one on the bottom left is my ground wire coming from the relay #86 (I also spliced another wire to this ground, which I grounded to my bike chassis) the wire on the bottom right is my high beam.

[IMG]local://upfiles/1672/012DAF6F43EA4B699FF213A1874DE719.jpg[/IMG]
Above: This is the Bosch relay- I bought the one with five posts, a relay with four posts would work, because I didn't use the one in the middle (87a). As you can see in the picture- the wire I labeled as my main power goes to the positive terminal of my battery- its #30 on the relay. You can see it better on last picture below.
I spliced another wire to my ground- one wire goes to the three prong headlight plug and other wire to the chassis- it is # 86 on my relay.
#87 is my accessory post- the yellow wire is fused and goes to my On-Off-On switch.
The picture does not show a good description of my #85 switch. This is what turns on my relay (actually #30 powers the relay, but #85 is the one that completes the charge- a relay is essentially a switch.) It is wired to my ignition, so when I turn on the bike, the relay turns on my headlight. I thought about wiring it to a switch and having the independance of turning on/off my headlights at will- but not right now. If you would like to do that, instead of wiring it to your ignition, make a jumper from the #30 to your #85 with a switch in the middle.

[IMG]local://upfiles/1672/7C53D50FB3964CE6A78CC539C4550074.jpg[/IMG]


[IMG]local://upfiles/1672/1366268711C34F08A932F08E595A8710.jpg[/IMG]
As you can see this is the bottom of the relay.
#30- I have my main power from the battery- with an inline fuse.
#85- This I connected a wire from my ignition.
#86- This is my ground. (Also, I have found out that you are limited to using 85 for power and 86 for ground- it could be the other way around-this is just how I chose to connect it.)
#87- This is the accessory or for what ever you chose to power up- in my case- rewiring my whole headlight system.
#87a- This is for constant power? from what I understand, there will always be power coming out of this terminal...thats why I chose not to use it. Please correct me if I'm wrong. I had no use for this terminal, so I skipped over this part.
More when I get back from a meeting.

 

Tong, I don't know if your 93's headlight(s) are like on my 90' CBR 1000F. Mine uses the Honda 45/45 watt bulbs. When one went out, I used brights for a while and then ordered some Candlepower 55/60 watt bulbs. I also bought the adaptors to mount the new bulbs (the Honda bulb's side prongs are at a different angle than standard H4's). But after cutting the prongs off, the spring clip holds the bulb securely, so you don't need the adaptor. With the higher wattage of my new bulbs, I may install a relay. Thanks.

 

I cant remember right now, but 50/60 sound right tho.
Tommorrow, I'll put up a parts list/number. I know this post would really other with headlight problems- like me.


Also, I'm am currently trying to look for some info on how to wire both hi/lo beam at the same time.
it really would help out on visibilty when riding at night.

 

On my old Suzuki, I could put the hi/low switch in between positions and have both high and low on, but only did it on very dark roads.

 

The way I have it right now wont work for me, but I'm pretty sure that it not really complicated- just need a little thought.


Here is a parts list of some of the items I bought. Most of these are from my local Checkers/CHK/ Kragens.
- 3 terminal headlight socket. P/N #85810
- Primary wire (10 gauge) 8ft. P/N #85700
- On-Off-On toggle P/N # 85919
- (2) Heavy duty fuse holder- blade type. (for 3 amp to 30 amp.) Cat No. BP/HHD
- “Baja Tough� Heavy duty relay-12 volts-30 amps. DF005 20-3529-8
- 208 piece Auto Electric Repair Kit by Calterm. Twin kit 05207 (I got this at the Base Exchange- they might carry something like this at Walmart?
In the repair kit, it came with a wire stripper, electricity light tester thingy, 22-18 gauge wire-which I used to a lot of.
- You may also need additional tools to take your fairing off -I already had my off. This allowed me access to all the wiring behind the front facial/headlight area.

 

Slowpoke, et al.: My old VFR 750F had those damn proprietary Honda light bulbs. A trick I used was as you're looking at the back/bottom of the bulb hold it with the one tab up @ 12:00, the other are roughly 4:30 & 7:30. Using a standard finish nail; place the nail horizontal at the base of the lower tabs; using pliars, fold both of the lower tabs up embrasing the nail. Voila! Your cheaper 4H light bulb of whatever wattage of your choosing now will fit into the light.

Cheers