Headlight Inop Update/Please Help

[dschmitta]

Hey everyone, I was dead wrong and have no clue what I was looking at when I posted. My h/light is inop, have neutral,oil lights. NO dash lights! Checked voltage on red/yel and blu/blk going into dimmer/relay. Have good voltage on r/y and NONE on blu/blk. Could I cut and splice the two together and have power to headlight? Not sure how to proceed.

[CaptonZap]

Check the fuses under the right side cover. If the label is still there, check the one that says headlights. If the label is gone, it should be the second one back, and if that isn't it, it is the third one back.
Hell, check them all, clean the contacts, apply some dielectric grease, and try the lights again.
CZ

[dschmitta]

Check the fuses under the right side cover. If the label is still there, check the one that says headlights. If the label is gone, it should be the second one back, and if that isn't it, it is the third one back.
Hell, check them all, clean the contacts, apply some dielectric grease, and try the lights again.
CZ

Sounds fair enough. I'm not a big fan of cuttin wires to begin with, just gettin a little frustrated and want to ride.

[GLoweVA]

The relay controls both the headlight and the dash lights.
If they are BOTH not working, then the problem is there or with the fuse.
Here's a pic with the schematic of the lighting circuit. The only difference is this is drawing is for the early models, the G doesn't have the (on/off) headlight switch and there's a diode in line to the AC Generator (aka altenator).

[DGXSER]

As George shows in his diagram, the power to the red/yellow is from the fuse, so if you have power at the red/yellow, your fuse is good. Sound sliek your relay has crapped out, or the diode in the white wire from the alternator to the relay is bad.

Either case, the simplest /cheapest solution is to eliminate the relay. The down side is you will now have your headlight on when trying to start the bike, added draw on the battery.

One way to prove if it is the diode or the relay, is to turn the key on. Then jump power from the red/yellow wire, yo the white wire in the connector. That should pull the relay in and light your headlight up. If it still does not light, the relay is bad.

If the relay is shot, then you may want to just cut the wires from the relay, pull out the white and black wires from the connector, and twist and tape, solder or whatever your choice, the red/yellow and blue/black wires together. Then put the connector back on the harness connector. Now you have a working headlight, and you can replace the relay if you so desire down the road.

[dschmitta]

relay bypass process question

Before I do this, should I undo Neg battery terminal, or will it be O.K. to do with connector just unplugged? Also, the white and black wires, do they need to be put back into connector before putting connector back on relay or just tape them off and leave unconnected? Thanks

[DGXSER]

It is never a bad idea to pull the ground off so you can not short the battery or electrical system when messing with the electrical components.

If you eliminate the relay because it is bad, what I meant is, take the connector apart. You now have the relay in your hand, cut the wires off the actual relay, so you have the relay side connector with four wires hanging out of it. Now, pull the white and black wires out of that connector that used to be attached to the relay. Take the cut off red/white and blue/black wires and connect them together. so now you hold in your hand the connector that fits the connector on the wiring harness on the bike, with only two wires, the red/white and the blue/black, and they are connected together like a jumper wire.

If you get a new relay down the road, pull off the modified connector, and plug in the stock relay connector.

[GLoweVA]

If you get a new relay down the road, pull off the modified connector, and plug in the stock relay connector.

+1 on that. I try to never cut wires on the existing harness. Either pull the relay itself apart, (ie disect the relay so you can use IT's plug/connections)
Or do like I did and build/make a jumper so you can plug the jumper into the harness plug pins. I used a short piece of 16gauge wire, crimped on a male spade connector on each end and inserted it into the R/W and L/B plug holes.
Thus effectively shorting the 2 leads together.
I know it's not perfect, but when the day comes that I can find the correct relay(78/79s are different than the 80/81s) or see if my diode(80/81s) is shot, then I can restore it back to the stock condition.

[skids]

If you put in a switched aftermarket relay, you can turn off the light(s) whenever you want to. All my bikes have this mod. In Colorado, you don't have to burn the lights in daytime hours. This helps in stop-n-go traffic jams and when you are just running the bike in the garage. It saves your battery charge and can make your battery last longer due to less frequent deep-charging. I prefer the switch at the left grip on the 78E, but you can get other switches for the relay.

[dschmitta]

relay

Do u have site where available? Thanks. By the way, did relay bypass, have lights and am stoked. Thank You sooo much for everyones help. much appreciated

[skids]

Do u have site where available? Thanks. By the way, did relay bypass, have lights and am stoked. Thank You sooo much for everyones help. much appreciated

Headlight relay is from any auto parts store. I suggest looking on ebay or somewhere for the 78E light switch if you want to do that. Much cleaner look. Dennis Kirk or others will have the handlebar toggle switch if you want to go that route. The switch runs off the low amperage side and the headlight runs off the higher amps side. The relay is nothing more than a simple solonoid that "turns on" the high side when the switch is activated.