I just bought a used 90cc quad that says freedom on the fender and BMX on the engine. Last problem i have is the lights do not work at all, the switch has three settings i'm assuming are headlamp and parking and off ? I know the fuse near the battery is good and the battery is new and fully charged , the quad starts and appears to be running pretty well and all other electrical seems to be working properly. I've only put power to the bulbs themselves and they work fine. So what I need is a lil troubleshooting advice. (I do have a meter and test light on hand) Any help would be much appreciated.

Thx,
chvyluvr

 

Some quads run the headlights off AC power directly from the stator. I don't know if this is true in your case, but what worries me is that if you headlights are indeed AC powered, and they don't work, then your battery charging system is probably not working either (it runs off the same stator winding through your voltage regulator). That would be a bigger problem than just inoperative headlights, because your new battery is not going to be kept charged.

For peace of mind, start up the quad and rev up the engine to a medium fast clip. Measure the DC voltage right at the battery terminals. You should see 13.5 to 14.5 volts DC. If you do, then we can focus on the headlights issue. If you read 12.6 volts or less, then you have bigger problems (but they are still solveable).

I guess that is the first step - determining if the headlights are AC or DC powered. Then we can go this way or that depending on the answer.

 

Thanks for the quick response. So I fired it up and the meter read just over 13V (13.1) at a medium clip with the motor cold (room temp. indoors)

 

I missed your last post entirely. Sorry for the delay in responding.

13.1 volts is sort of low. It is greater than 12.6 volts so at least some battery charging is being done, but it will take your quad a lot longer to top off the battery after the engine starts. Perhaps we want to revisit this after you headlights are working.

My quad headlight switch has three positions also - off, low beam and high beam. Does your headlight(s) have three wires to them? If the do then you have low and high beam too.

If you look at the wire colors at the headlights coming out of the wiring harness, you should be able to figure out which color is ground (look at the color of all your other ground wires). Then look for the other wire (or two wires if you have three) at the headlight switch. Then unplug the switch and use a meter to find out what these wires tie to when the headlight switch goes through its motions. Note that color and look to see if the same color is also at the ignition switch or at the stator. The philosophy is that a wire color that enters the wiring harness will still be the same color at the other end where it emerges (pretty reasonable assumption I think). In addition, almost all quads use a different wire color for each function - grounds are all the same color, switched 12 volts are all the same color, kill switch wires are all the same color, etc. By looking at where the headlight source wire comes from (stator or ignition switch) it will suggest whether the headlights are AC or DC powered.