I started searching this forum and realized I am completely lost.

My son has a Chinese quad 90cc, just the other day he's riding goesover a rock and it's dead. the light's don't come on when the key is turned and he get's no starter power. I jumped the on off switch (not the key) and was thinking this is either the safety in the rear or the alarm ? and I was thinking I can just disconnect both to get it running.

I of course have no idea how these 2 items work or if it will help.

Please advise

 

Check the fuse. It will be somewhere close by the battery. On a few quads the fuse is built into the starter solenoid, but this is still close to the battery. Check the wire connections at the battery to see that they are clean and tight.

Also follow the wires from your ignition (key) switch. They should go to a plug before entering the main harness (sometime this is under a plastic panel). Make sure it is plugged in tightly and all the pins are making connection.

Also try this: Set the parking brake. Put the quad in neutral. Follow the heavy gauge wire from the positive battery terminal (fat red wire). It will go to one of two screw posts on the starter solenoid. The other screw post on the solenoid will continue on to the starter motor. Short these two screw posts together with the shank of a screwdriver (some sparking is OK). Does the starter motor turn? Turn on the ignition and repeat this test after double checking that the parking brake is set, and the transmission is in neutral. (You don't want the quad taking off on you unexpectedly should it manage to start up). Does the quad start when you short the two posts?

 

Thanks Lynn here's the progonosis

1. Fuse is OK
2. Plugs all secured
3. Jumping the solenoid did nothing

Normallly when you turn on the key switch the back brake light comes on. Now nothing. The odd thing is when the lights are in the on position and you turn on the key switch they come on. Does that mean that the switch is working and something else is stopping the electrical power?

 

When you said no lights I assumed no 'headlights'.

There is a starter safety interlock on your quad. The starter will not engage unless the ignition is on, and the brake is pushed (i.e. the brake light is lit up). Your brake light is not lit up, therefore the starter will not engage. Try playing with the brake switch(es) and see if you can get the brake light to come on.

Is your brake activated by handlebar levers (front and back), or front lever and back foot pedal? Try both brakes to see if you can get the brake light lit up (ignition switch on of course) before pressing the start button.

There is a conflict in your last response: You say the headlights work, but nothing happens with you jump the solenoid. When you jump the solenoid you are manually connecting the starter motor straight across the battery. The starter should turn - no matter what - unless the battery is dead. Maybe you have two problems: A mostly dead battery that can muster up enough power to run the headlights, but collapses under the much heavier starter motor load. Leave your headlights on and jump the solenoid again. If the headlights go out then the battery is dead. Jump the quad battery to your car with jumper cables and repeat. Does the starter turn when you jump the solenoid with your car tied in with jumper cables?

Remember that whenever you jump the solenoid have the brake set and the transmission in neutral. You are bypassing all the safety interlocks when doing this, and you want the quad to stay put if it should start up.

 

Brake switch it is. Your a genious thanks and my son thanks you too

 

 

The problem has resurfaced. The brake switches both activate the brake light but the starter button doesn't turn the starter. I did get it running jumping the solenoid but I don't get what's stopping the starter from engaging? is there another switch? I suppose it could be the actual starter switch too?

 

The starter solenoid is just a big relay. When you apply 12 volts across the two small wires feeding the solenoid it feeds a coil which generates a magnetic field - which sucks down a steel plate - which shorts the two studs just like you did with your screwdriver to jump across the solenoid.

On your quad one end of the starter solenoid actuating coil (small wire) is grounded all the time (you can verify this with an ohm meter). The other wire gets 12 volts through the brake switch and then through the starter button. You have brake lights, so the only thing left is the start button or wiring (or my assumptions are wrong).

To test my assumptions and the wiring:

1) Turn on the ignition and set the brakes. Verify that the brake light is on.

2) Measure the voltage at each *small* wire feeding the solenoid to engine ground. What voltage do you measure at each of two wires?

3) Press the start button and hold the button in for the following tests. Repeat step 2 above and report both voltages (holding the start button in). What do you measure?