How to test headlight relay off the bike?

[njcafe84]

Im having some electrical trouble and want to test the headlight relay.

how do I do this? The relay is off the bike and want to check it with a volt meter but Ive never done this before.

Check resistance? What should the readings be if its working fine?
these sort of answers will help me a lot

thanks guys

 

[TimmyT]

send 12 volts to it and see if your hear the relay click to close the circuit which is normally open unless the 12 v is applied. I would only speculate if it fails the circuit will remain open or have some intermittent closure, which means 12 volt applied and the light might work half assed or only sometimes, or just plain not at all. If anyone knows any other way to test this relay please chime in. I myself am trying to get my bike goin for springtime and as close as I am I still may have to do some inspection here.

The headlights draw lots of power so the relay is supposed to click in after startup to not interfere with the battery until the startup process is complete. I have heard several times the headlight wont work until after the bike is running. This leads me to believe I have an issue here somewhere as my headlight works just fine, but the bike wont start atm. The wiring could be another potential issue, functional relay and bad wires on the harness wont do anyone any good. Does the relay close when the key is turned and operation is interrupted duning the startup process, or can the relay fail in a closed position thus the headlight is only off when the full lighting system is in the off position? this time around if it does not want to start for me after only a few kicks I would guess If I disconnect the headlight system it will most likely startup ... im just a day dreamer I guess.

 

[arfstrom]

When I had ordered a new relay, (I sent it back) I just switched the relays from one the safety relay, to the headlight relay. I heard a snap, and shazam my lights were on. Then after the bike was running, I swapped the relays back, and everything was ok.

So to check the relay off the bike, Get a 12v battery, look at the wire diagram, on wire is coming from the fuse and is supplying 12v to the relay, connect that wire to that post. connect a test light on the opposite side, power feed wire to the head light.

Test light needs to be connected to the neg post on the battery. That will complete the main power feed circuit.

So unlike the car, this system has no computer, so that means everything is 12v. only difference is the that main power feed is coming from the stator. So my thought is another wire from both post of the same battery should do to create a second circuit. So on the ground side of the relay weak side that would be going to the neg post as well, then with the extra wire, A touch of power to the activate post of the relay will cause a pop, activating the eletro-magnet to 'on position', and which will turn on your test light.

I haven't done this so I don't have the which wire is which, but you should be able to figure it out with the right wire diagram. I still think if your bike is running, just swap the relay, if your bike isn't running, wait till it is, and then worry about that. Chances are it is fine. That car statement just meant that the electric-magnet effect is created so that it doesn't need as much energy to though the pole to the on position. since our bikes are straight 12v which is why i don't think you would hurt anything with this setup.

Both what Timmy and I are saying that you will need to make sure you have a clean grounds. generally corrosion will cause ground issues which can be on either side of the wire. So always check and freshen up your clean grounds. (Battery, Seat post near battery, and where the battery grounds out on to the engine.
good luck

 

[njcafe84]

Thanks for the reply guys...I got the headlight working but it turns on with just the ignition key instead of once the bike is running