Headlight problems

Hey guys-this one should be pretty easy for you. All of a sudden the headlight on my '82 Seca 750 comes on with the key on & ignition off-(never did this before)- & turns off when engine fires. I could probably figure this out but I am so burnt out from battling an intermittant ignition problem I cant think straight anymore. Any ideas? thanks

 

Burned headlight relay maybe? Either find the relay and replace it or bypass. The Maxims never had a headlight relay to begin with, we seem to be fine.

 

It sounds to me like a new ignition switch may be in order, My engine would cut off intermitently when I hit pot holes or speed bumps and the bakelite/epoxy case of the switch was cracked. My seca headlight is suposed to come on only after the engine had cranked and the key is . left in the on position. Either way the flow starts at the switch.

 

Hey thanks alot for the ideas guys. I suspected the relay as well. Just looked it up in the catalog-$80 for a new one. Time for some creative re-wiring maybe if cleaning the old one dosent work. Does anyone know if the aux. light (which i dont have on there anymore) is tied into the same headlight circuit? I'm horrible at reading schematics.

 

AUX switch is it's own thing, you could rewire the switch for your headlight and bypass the relay but still be able to turn the key and start before the headlight comes on. Just cut the AUX switch out before that big plug, put the Red/Yellow wire from the fuse into one side of the AUX switch, put the other side of the AUX switch into the Blue/Black wire going into the dimmer switch on the bar. That way, the entire headlight circuit goes through the AUX switch before the LOW/HIGH dimmer.

Just remember to turn your headlight on before you ride off! Could even mod the switch words a little bit, at least sand off the AUX lettering.

 

And there it is! Thanks much BlkMage-you saw where I was going there. Great information-I love this site! If I have to go this route I may add an indicator light somewhere to remind me if the headlight is on of off. I certainly dont have $80 for a new relay-geez thats 4 tanks of gas! Thanks again-happy trails, all.

 

Great thread! I think this will be my solution too. My relay is dead and I am unable to get it to work by bypassing the relay either. But both my bulbs could be dead.

I think using the Aux switch as a manual on/off is a great idea.

 

If bypassing the relay doesn't make it work, how do you know the relay is "dead"?

One other thing to consider here is that the AUX lamp is 35W = 3A. The headlight is 55W/60W = 5A. If Yamaha didn't over-spec the AUX switch, it may not last that long carrying the extra current directly... i.e. you might need to add a relay to help carry the load.

I'd really like to know more about what's really wrong with WWJ750's system. The behavior certainly seems to indicate a relay that's switching on and off, albeit incorrectly. I would more suspect the diode block than the relay.

 

BTW, WWJ, if you want to directly test the headlight relay before starting the bypass work (assuming it's not already too late), here's what you need to do:

1. Disconnect the W/L (White/Blue) wire at the headlight relay.
2. Turn on the ignition - Headlight should be off
3. Momentarily jumper 12V to the pin on the relay where the W/L wire was connected - headlight should come on and stay on

If this test shows what I've listed as the expected behavior, then there's nothing wrong with the relay, and the likely culprit would be the diode block or some recent change to wiring.

 

Good point. I truthfully need to track all the wire down first and see if there is a short.