I'm new here but not to quads and motorcycles. I have a 2004 90cc xtreme tantrum with electrical problems. As soon as I turn the ignition key the fuse near the battery blows. I have disconnected the lights and brakes checked for damaged wire etc.

Is it possible that one of the electrical components (CDI, relay etc) could be causing this or should I keep hunting wires for a short? I hate to have to unwrap the whole wiring harness.

Any help appreciated!

 

What is the value of the fuse?

Look at your blown fuses. Look at the fuse element inside the case. Is it sort of melted in the middle with a narrow broken gap, or is the fuse totally creamed - with a wide gap and a silver or black sheen all over the inside walls of the normally clear fuse chamber?

Unplug the voltage regulator, and put in a new fuse. Does it stop blowing when the regulator is unplugged?

Don't unravel the wiring harness. That is almost certainly unnessary, and won't give you any useful information.

 

Thanks for taking the time to help with this Lynn.

The fuse is supposed to be 7 amps (I think) but I have been testing it with both 5 and 10 amp fuses since I have a number of them available. 5 blows quick and leaves residue. 10 blows in a melting sort of way but also leaves a big gap and residue. I tried it for a few seconds with a 20 which started to melt but I almost immediately got smoke out of the switch that senses whether the brake is set so I pulled it immediately.

I disconnected the voltage regulator and it blew both the 5 and 10 amp same as before.

Thanks again for your time. This gremlin is driving me nuts!

 

If there was a good solid short to ground then the fuse would go off like a flash bulb - painting the inside of the fuse the the fuse element, and leaving wide gaps between the two fuse ends. If it were just a moderate overload then the fuse would take several seconds to a minute to blow (depending on the degree of overload), and the fuse would glow red in the middle for a while and then open up with just a small gap across the fuse ends.

It sounds like you've got a really low resistance short, but not a dead solid short .

Normally the procedure in cases like this would be to unplug everything - i.e. every connector on the wiring harness. At this point the fuse shouldn't blow. Then plug in only the ignition switch connector. This is first because everything that is powered off 12 volts comes through this switch - other than the starter, the remote control module, and sometimes the regulator. If the fuse doesn't blow then turn on the ignition switch. If the fuse doesn't blow plug in the remote... Then the regulator... then everything else one by one until we find the connector that blows the fuse. That gives a big clue as to where the problem is.

You took a somewhat different route by plugging in larger and larger fuses until you got smoke. This is not the recommended way to troubleshoot blowing fuses, but smoke is also a big clue so let's go with it .

So the brake switch has too much current going through it. Was this the front brake switch, or the rear brake switch?

Unplug the brake light, the remote module (if you have one), the two small wires going to the starter solenoid, and the connector to wherever the start button is.

If the brakes are not applied do you still blow fuses (I'd stick to lower values like 7 or 10 amps)? If it doesn't blow fuses with both the brakes released, then does either brake switch blow the fuse, or just one of the two?

If no fuses blow then plug in the connectors disconnected above on by one, repeating the last test at each step. At some point the fuse will blow. Document that and we will hopefully be near the sources of the problem.

 

I had the same symptom with my E-Ton YXL 150CC. It turned out to be a disconnected ground wire at the head lamp. Just saying.

 

Resolved!!!!

Thanks for all you help. Backtracking from the brake lights didn't solve the problem. So I went with Lynn's recommendation of unplugging everything and then started with the relay to the starter. That blew the fuse so I chased the wire and found out that it was spliced and went forward again toward the carb. Turns out some yahoo (maybe me) plugged the spliced wire directly to ground. I think some of the connections must have come loose on the last ride and the field repair was botched.

In any event I've now replaced the spark plug, cleaned the carb, and the little two stroke is working better than it ever has.

Thanks for taking time to help.

 

I'm glad you got it working

 

As soon as I turn key fuse blows. I've unplugged everything except ignition switch and still the same thing. Took off complete harness and all looks good. Any help would be great. Thanks