Ask the Editors: Electrical System Stalls
Ahh electrical anomalies. Ordinarily we are forced to answer these questions with a whole bunch of questions of our own and this instance will be no different. To begin we notice that you say it exhibits this behavior “sometimes”; have you ever made any connection with what’s going on with the quad when it does this? Does it seem to be completely random? Only during extreme heat or cold? Does it do this if you hit either switch at engine idle? What about when you’re moving/ working the engine?
All of these factors are very significant in helping to determine the cause and possible cure of the condition you are experiencing but even without such details, we can make some educated assessments. Ordinarily an engine stall from an electrical drain indicates insufficient charging. Assuming you are starting with a good, strong battery (you can always check this with a simple voltage meter), fire up the quad and let it idle.
With your engine running, it is possible that the stator is faltering and even though the battery is sufficient to start the machine, any sudden electrical draw pulls enough amps to shut down the whole system. Grab that volt meter and put the red lead on the positive post and black lead on the negative post and see what it reads at idle, then rev the engine a little and see if there are any changes.
You should read around 12V DC on a properly charged battery. Once the engine is on and revved, expect around 13 or 14V DC indicating the battery is good and receiving a charge. If there is no change present or a dip in the voltage, the problem lies within the charging system itself (stator, regulator or associated wiring).
If this checks out, we would usually begin the always-exciting task of checking all your machine’s grounds. You do this by locating the wire cluster coming off the battery’s negative terminal and trace these to make sure every connection and frame-attachment point is good and secure. Don’t be afraid to clean up any rust and corrosion you may spot. Having good ground contact is crucial when it comes to electronics. We have heard of strange cases where water getting into a wiring harness was the culprit of seemingly random electrical troubles.
If all of this checks out, we would then start to consider the possibility of a short. This is fairly unlikely because you say the problem isn’t consistent and we assume after it does stall, the ATV fires up and acts normally again? To check for shorts, we use the tried and true method of starting with a 12V automotive test light. Clip the end of the test light to the negative side of the battery and place the probe at each wiring connection starting at the positive-side harness. If the light goes off, you located your problem.
