OK, so a few mornings have been cold here in Florida lately. My gs's battery would chug along, and take 4-5 attempts to start the bike. Now on that 5'th attempt, it gets s l o w e r.

So I decided to interrupt the headlight circuit with a relay to kill the headlight whenever the starter relay is energized. No big deal right ? I'm no electrical engineer, so I had to dig a little bit to find a howto.

1) Decide if you have the skills to use a screwdriver, crimper, and possibly soldering iron.
3) Are you colorblind ? Find a hot chick/ friend that isn't to help.
4) Yes, I know I skipped 2)   -- Who cares ?
5) Go buy a 30 amp single pole double throw relay ( autozone sells one for like $9 ).
7) Ya, I skipped 6 too.
Plop the headlamp on the ground.
9) Splice on a connection to the Green / Yellow lead, and attach it to 85.
10) Connect 86 to ground.
11) Interrupt the ground on your headlight circuit (black/white) and connect one side to 87a, and the other to 30.

If it all fries, it's WalMart's fault, not mine, damnit.

If it works, and you like it, send $4 worth of Ramen to my paypal.

You should see a noticable improvement in starting power. Cold days be damned.

If anyone knows of a better way to do it, feel free to use and abuse this thread.

It's really cool to here the bike CA-PALOW on the first hit of the starter now, even on cold mornings. 


**** info added care of kml.krk - thanks ! ****

Quote from: kml.krk on November 13, 2011, 09:11:54 PM
I did not manage to install the relay last year but I finally did it last night. I followed instructions posted on the first page BUT the yellow green, or green yellow wire is absent on 2004 model so I had to find one that energizes starter button. I checked wiring diagram fore F models and found out that the wire is half yellow, half black and can be found bundled with few other wires under tachometer. Just follow wires coming out of starter button and you will get it.
I really hope that this will help with starting the bike on really cold days.

if a few people would like to add what year they have, and wether this interrupt is already present, that would be much appreciated.

Hey, where are you in FL? I'm in Sanford, and looking for good places to ride besides to work everyday.

Ah, how about a battery that works? I'm in sc, bikes outside. I'm sure its colder than fla. Sounds like your battery needs a charge or dumpster.

Regardless of battery condition, still a cool idea. 

Interesting idea, might have to do that.  It was 10 out a few days ago and she didn't want to go.  It's going below 0 again tomorrow, so we'll see...

hehehe, you poor schmucks in cold weather... :cheers:it's in the 40's here at 12am...


that is a cool idea though. the hardest thing on a battery is startup so having one less thing drawing power is a great idea. and it may end up prolonging your batteries life, theoretically. (idea being that if the battery is drained less and charged less, it's not going to wear out as quickly.)

as a more basic option, could one just install a manual switch for the head light?

Quote from: galahs on February 07, 2007, 01:49:44 AM
as a more basic option, could one just install a manual switch for the head light?

Technically illegal here in the US... however, yes, you could..

then you still have to worry about mounting a switch somewhere. This is the best option because #1, you won't have a switch to mount, AND FORGET TO TURN ON. #2 it's not hard to do at all. pull the headlight, find the wires, cut, crimp, plug, put on headlight and wammy, you're done.

cars it's a bit easier because you can just run it to on position only, not to the starter position of the ignition switch, but with a bike, you only have 2 on positions, rather than the standard 3 of most cars. (parking and on for bike, acc., on and start on cars)

Excellent idea.  I am gonna do it this weekend.  I love relays.

Quote from: walkingman on February 06, 2007, 02:38:21 PM
Hey, where are you in FL? I'm in Sanford, and looking for good places to ride besides to work everyday.

I'm in the Tampa 'burbs. Other than ANYWHERE NORTH of Tampa, I'm thoroughly convinced that there are NO curvy roads in the state of florida. Everything is straight, flat, boring and occasionally sandy, just to keep you awake.

Ya, I commute/play/f$ck-off on mine every stinkin day, rain or shine.

Actually, there are a few harley type bike get togethers in Lakeland, and every other little previousely traintrack'd town. If you can stand the congestion and lack of real riders, not to mention gaudy paint, it's pretty cool I guess.




Yes, I'm chargin the old bat' tonight. This coming weekend I'm installing another relay for accessories and charging stuff/running stuff (cellphone/laptop/camera/whatever). I welded (welded is a very very generalized word here folks) up a nice (again, generally nice) gas tank camera mount at the machine shop I worked at a while back.

I'll post some pics sometime if anyone wants an idea how ugly stuff can get.

Quote from: ohgood on February 06, 2007, 01:26:20 PM
...............................9) Splice on a connection to the Green / Yellow lead, and attach it to 85. .............................

Do you mean Yellow/Green?

If you splice to the Green/Yellow your light will go out if you loose oil pressure. That shouldn't happen and likely won't, but .................. it's possible.

I should check my wiring diagram on that note. I punched it all in here from memory, so you're likely correct.

Also, if oil preasure is gone, I doubt the headlight dimming/dying will be the least of your worries.

Safety first, I'll check later today.

thats a great idea. some bikes come like that stock, like my c50.

definatly cool idea. the only reason I say the toggle switch would be a cool idea is because you can be sneeky on your motorcycle and kill the lights at night , like james bond style haha. I think I am going to have to do the idea you came up with so . sounds sweet

I saw a guy that had a switch installed that would kill ALL his lights...  Headlight, taillight, dials, everything...

He called it stealth mode...   

muahahahahahaha its 68 degrees outside right now at 3 am it hits a high everyday around 80 ish. And cuban cigars are leagal 

Quote from: thatguy1025 on February 10, 2007, 02:07:16 AM
muahahahahahaha its 68 degrees outside right now at 3 am it hits a high everyday around 80 ish. And cuban cigars are leagal 

Evidently, literacy is not the norm, however. Also, you get taxed out the ass for Cubans. So  right back. 

Quote from: thatguy1025 on February 10, 2007, 02:07:16 AM
muahahahahahaha its 68 degrees outside right now at 3 am it hits a high everyday around 80 ish. And cuban cigars are leagal 

my grandmother was from hondurous.  I want to go back to visit all my relatives (sp)

can anyone confirm that this is correct relay:

http://cgi.ebay.com/1-12V-DC-Bosch-OEM-Standard-Relay-SPDT-30-40-Amp-/190471721898?pt=LH_DefaultDomain_0&hash=item2c58ffd3aa

thanks