Headlight rewire w/ relays

Anyone happen to have the headlight wiring diagram for an '82 550 ltd?

I picked up a heavy duty H4 bulb harness (The bike already had an h4 conversion) and a couple relays to counter the 3.7v drop between the battery and headlight, wired everything correctly, but the two wires that tie to the high beam side are giving me trouble..with the old plug/wiring, two wires connect to the high beam, one is from the switch, and the other seemed to me like it was supposed to trigger the dash light, but using the relays, the dash light is on all the time, and gets brighter when the high beam is turned on. If I disconnect this lead, the light on the dash stays on, if I ground it, the relay clicks and the dash light goes off, but the high beam turns on, and its a bit brighter than if the high beam switch were turned on..If that made any sense..:blink:

The wiring would be very simular to WG Coil Mod only instead of hooking it to the coil feed you would use the headlight wires ,,,, Low beam would go to one relay and high beam the other relay .. Both Relays could get thier power from the the Starter Relay if you like the other sides go to the low and high beam terminals on the headlight .. one of the haedlight terminals on the back of the headlight is a ground ,, I really dont remember But I think it is black with a yellow stripe ?? Or a wire connects to a Black and Yellow stripe ? If you look at your relays there is a diagram on the tops .. showing which terminal does what they are numbered to ,, 87 86 you can clearly see the high voltage sides as they would be the ones with the open or looks like a draw bridge ,, Your power would hook to one side and the your headlight the other ,, the other terminals will be the control side of the relay one side would go to the headlight wires low/high beam ,, the other sides would go to a good ground , Looks like your dash light is back feeding ,,Might want to check all tthe connections over again just to be sure I am sure you are confused now ,,,

Post edited by: Shoe48, at: 2007/01/08 01:40

I had the same situation including the High beam indicator light symptoms. The cause was in the High/Low switch gear. Long-story-short, designed my own head light relay mod, installed it and tested it for a few months. Worked out fine and cheaper than new switch gear.

I made a wiring diagram. I don't know how to post it so if you PM me with your email address and if you ISP will accept large files I'll be happy to forward it. Your bike's wire color code may or may not be identical but its a start.

Either way let me know. Best of success!

To install the relay, connect it to a pigtail so you don't have to put connectors on the relay directly. They will fail from oxidation. Use a fuse between the battery and power IN on the relay. There will be a BLUE wire currently running to the hi/lo switch inside your switchgear. This wire will be the trigger wire for your relay. Use the power OUT of the relay to go to the hi-lo switch. The switch will put this power onto a red/yellow wire or red/black wire. They are the low and high beam wires that will run to your headlight bulb holder. The high beam wire will split and run to the high beam indicator idiot light. See the coil repowering article on our web site for the actual pin numbers for the relay. Put a switch inline with the power OUT wire unless you want to run the headlight all the time. I don't think the headlight can be turned off on your model otherwise (NO on/off switch on the right switchgear).

I know the relay is wired right, and the new headlight feed is 12 ga. I think I'm just going to ignore the dash indicator for now, the headlight itself works fine as is.

State law in Missouri requires you to run the headlight all the time anyway, so theres no reason for me to turn it off.

Werewolfx wrote:

State law in Missouri requires you to run the headlight all the time anyway, so theres no reason for me to turn it off.

Unless you're hiding from the fuzz. Not that I'd know anything about that.....:woohoo:

Post edited by: caffcruiser, at: 2007/01/08 17:10

Just a last word of caution... you may want to check more closely to be sure that both High and Low beams are not on at the same time. It could be hard on your battery and or charging system. I believe that is what was originally happening to mine.

Best of success.

I know the high beam isn't on all the time, I do almost all of my work at night, and all of it is done outside, that was the first and last thing I checked on.