Head Light relay Help!

[randy]

Rick, you might as well just replace the whole relay rather than the individual parts. But, if you're so inclined, those parts are resistors.

[Ken Talbot]

FYI - here's what a diode looks like on a later-model machine.

[randy]

Standard Aftermarket Automotive Relay

WILL turn on IF you install the diode in the yellow wire. Did it this morning and it worked. Diode doesn't need to be this robust, but it's what they had..a 1 Amp diode would be plenty strong.


Engine off, open circuit, engine on, meter is reading 0 Ohms across the switched contacts of the relay.

[esw1104]

dummy from peterborough cant turn a light on

its been a while since xs north(2009) but i found my way back to my bike the other day and got it running nice (nicer anyway).

I added a 4 into one header and found some lost power in the 1500-2500 range that i had not realized was missing. I was all proud of myself and drove 500-600km to reward myself. thinking all was great i decided the bike should come to work with me a short 126km trip each way. well i get up at 5:00am and go out all ready for work and start the bike .... no head light. (you where wondering when i would connect with this thread) .

After two hours of friendly time with my multi-meter i thought to check xs11.com and found these smart sounding folk and thought maybe they could help me

anybody fell like walking a fella thru some relay tests

[Rickrod3]

Thanks alot Randy

For the latch circuit would you jump the yellow to blue?

Rick

[esw1104]

is this my headlight relay?




And how exactly do i test this thing?

Wow got to learn to size these images

[Rickrod3]

its been a while since xs north(2009) but i found my way back to my bike the other day and got it running nice (nicer anyway).

I added a 4 into one header and found some lost power in the 1500-2500 range that i had not realized was missing. I was all proud of myself and drove 500-600km to reward myself. thinking all was great i decided the bike should come to work with me a short 126km trip each way. well i get up at 5:00am and go out all ready for work and start the bike .... no head light. (you where wondering when i would connect with this thread) .

After two hours of friendly time with my multi-meter i thought to check xs11.com and found these smart sounding folk and thought maybe they could help me

anybody fell like walking a fella thru some relay tests

Well just going threw this I'll give you my 2cents.
first check the fuse. then I would check the bulb
If that is okay under the tank is a head light relay.
This seems to be the place that most have a problem with.
In my case it was the cause of the 10 amp fuse to blow out.
You can jumper the blue and red wire turn on the key and if you RLU is working you head light should come on.
In my case when I jumpered the blue and red wire the head light came on and fuse would not blow.

If your light come on after the jumper I would check the yellow on earlier models white on later models when you start the engine. if you have voltage there your problem is in your relay.

Randy just posted a replacement option. if you have the yellow wire you can check his post out.
If you do not have voltage and you have the white wire it could be a diode in the harness. do a search for diode and look for a post by Ken Talbot it has info and pictures there is a link to it in this thread.
There is even a thread to bypass it but I think its better to have it work.
HTH
Rick

[esw1104]

ok ill try the red blue jump.

Yes i checked the fuse
yes i checked the bulb.
oh i re-soldered to hazards after running wires and found some bad connections in left handle bar.

will see what happens with red-blue ?

[esw1104]

well bulb came on kind dim

started bike and got better.

so just a bad relay then is this the pro diagnostic?

wonder if the parts bike in the attic has extra ... im too cheap should just buy new one

oh well day riding only for a bit i guess

wonder why my dealer dont keep more 1979/80/81 partds in stock for me ?

[Rickrod3]

well bulb came on kind dim

started bike and got better.

so just a bad relay then is this the pro diagnostic?

wonder if the parts bike in the attic has extra ... im too cheap should just buy new one

oh well day riding only for a bit i guess

wonder why my dealer dont keep more 1979/80/81 partds in stock for me ?

Before you condem the relay check for voltage at the white wire once the engine is started it could be a bad diode.

[esw1104]

hmmmmm 0

well pleasing my neighborhood to no end i started the new mac 4-1 header equipped bike up and

0 volts on white

well it sounds good anyway but no light

Does that mean i have a diode in line on my 79/80/81 jonnie cash machine?

oh joy i get to unwrap my wiring harness you know i wanted to do that rather then ride

[bikerphil]

BTW, the voltage on your white wire from the Alt will be in AC voltage with the bike running.

[esw1104]

alas yes ac and dc .... no voltage ..... 12.46 on red though

most schematics i have point to the secret existence of a diode somewhere in my harness

My Photo Link...

http://s274.photobucket.com/albums/jj271/esw1104/

[randy]

For the latch circuit would you jump the yellow to blue?

That's correct.

[bikerphil]

Well you have 3 options:

1. Rip the harness apart and find the burnt diode.
2. Run a new wire from the alt plug to your relay with a diode in line.
3. Bypass the relay and be done with it.