Headlight not working with RLU bypass

[dzeko]

Yamaha xs650 1981 - headlight does not work.

I got rid of the reserve lighting unit last week, bypassed it with two wires and light turned on but very faint. This week i used a female bullet connector that actually fit ( blue/ black + blue/yellow) and now the headlight won't turn on. Thoughts?

Battery is fine. Voltage is fine. Headlight is brand new and it works ( tested with battery). Checked the fuses and they're all fine.

 

[dzeko]

Here's a pic from last week when it lit up a bit

 

[zrx1100]

when I did the bypass, I remember there were a number of conflicting instructions on the web. Here is how I did it for what it’s worth.

 

[dzeko]

Looks like I'm only reading 3v from both high and low beam connectors via the headlight bucket. I bypassed blue black and blue yellow, fuses all check out fine. Could it be the headlight safety relay?

 

[zrx1100]

what year is your bike? on my 78 there is a switch on the right handlebar that turns the headlight on and off. if you have it , make sure it is on to test the headlight. otherwise, try starting the bike to see if your headlight turns on

 

[5twins]

Yes, I guess it could be the headlight safety relay. With the bike running, test the voltage on the blue/black wire coming out of the headlight safety relay and feeding into the RLU. It should be 12V.

When I add jumper wires, I like to make them just long enough so that I can pass them through the wiring coming out the back of the plug. This effectively holds the jumper wire in place and it won't easily unplug if snagged on something .....

To make these up, I have several old junk harnesses I'm able to clip wires w/crimps from.