Re: Request - Austin help on Baja Designs wiring issue CRF250X
Tj. I am hoping that you know how to at least check voltage on your multimeter? If you do the first thing is to put the multimeter across you battery and make sure it reads 12+ volts, we now know you battery is okay and that you do have your multimeter on DC voltage reading!!
The following steps should be followed:-
1) all the power for the headlights comes from a seperate alternator winding (called the lighting coil, bottom right hand corner of the schematic), if that coil fails you will have no lights. the easiest way to check if the lighting coil is working is to start the engine and you should see the tail light come on (it is not switched so as long as the bulb is good, it will light up as soon as the engine starts. If the light comes on then you need to go to the next step, if the tail light doesn't come on when you start the engine, it would seem the lighting coil has failed (probably have to get it rewound by Baja (not cheap).
If the tail light did come on, then:-
2) check you have a negative/ground at the headlight, to do this leave the positive lead of your multimeter connected to the battery positive terminal, and connect the black negative lead of your multimeter to the negative/gnd connector on the headlight bulb (black wire according to the schematic). If the multimeter shows 12 volts then you have a negative connection so you can move to step 2, if the voltmeter shows less than 12 volts then you have a bad or no connection. You need to follow the black wire until you find where it is broken or disconnected.
3) According to the schematic there is no relay in your headlight, the hi and low beams are powered directly from the headlight turn signal switch shown at the bottom left of the picture in a dotted rectangle. this indicates that power to hi and low beams comes into the switch on the Y/R (yellow/red) wire. So the next thing is to check that 12 volts is present on this yellow wire. Connect the black negative lead of your test meter to the battery negative terminal and open up the left hand switch unit on the handlebar and find the headlight switch, then find the yellow/red wire and connect the voltmeter to it, check the ignition is turned on and the engine is running, you should see 12 volts present on the Y/R wire. if you do and the headlight is not lighting up, then we need to find if the wiring between the headligh and switch is bad, or if the switch has failed.
4) Put the headlight switch into the Low position and check that you have 12 volts on the Green wire (the green wire powers the low/dip side of the headlight bulb), if you don't then the switch is faulty and needs cleaning/replacing, if you do then either you have a faulty wire between the switch and the bulb or the bulb is dead. Then put the headlight switch into high position and check that you have 12 volts on the yellow wire (the yellow wire provides power to the high/main side of the headlight bulb), again if it shows no volts then the switch is faulty, if it does show 12 volts then you have a wiring issue in the yellow wire between the switch and the headlight bulb, or a dead bulb.
5) if you did not see 12 volts on the y/r wire then the main supply for the headlight is faulty (I suspect this is your problem!!). Unfortunately I cannot understand from the schematic, what happens to the Y/R wire after it has connected to the multi pin connector in the very middle of the schematic. It looks like it goes to the FET, but I have no idea what an FET is (I suspect it's a diode to half wave rectify the Lighting coil output). All I can suggest is that start the engine and connect the poitive lead of your multimeter to the orange wire where it connects to the FET (leave the negative lead of the multimeter connected to the battery negative terminal. if you see 12 volts then it would seem the FET is working and you have a problem with the orange wire between the FET and the headlight Hi/lo switch. If as I suspect you do not see 12 volts at the output of the FET (Orange wire) then either the FET has failed and will need replacing, this assumes that your tail light came on in test 1 above. If the tail light did not light up when the engine started, then the generator coil is defective and none of the lights will work.
Hope that helps a bit, if you where near Dallas, I would be happy to come and help, but Austin is a fair way away..
Gary
Welcome to the Two Wheeled Texans community! 
Feel free to hang out and lurk as long as you like. However, we would like to encourage you to 
