I AM LOOKING FR SOME HELP WITH A FUSHIN ATV 90... MY SON WAS RIDING IT FINE BUT THEN CRANKED THE INGNITION SWITCH TO HARD AND BROKE THE TUMBLER. IT IS A 4WIRE PLUG WHICH I ORDERED A NEW ONE... I REPLACED THE SWITCH AND CHECKED THE BATTERY (WHICH IS SHOWING BETWEEN 15.5-16VOLTS) SO THE BATTERY AND FUSE ARE FINE BUT WHEN I PRESS THE IGNITION BUTTON I GET NOTHING? THE BRAKE IS HELD IN AND THE EMERGENCY PLUG ON THE BACK IS CONNECTED... CANT FIGURE OUT WHY NOTHING HAPPENS WHEN IT RAN FINE BEFORE... ANY SUGGESTIONS WOULD BE GREATLY APPRECIATED.. THANKS

 

First of all your meter is broken. Batteries cannot put out 16 volts when the engine is stopped. Check the internal battery in your meter. A really low battery can make all meter measurements read too high. Else see if you can find a working meter.

Some things to try:

1) Turn on the ignition switch and apply the brakes. Look at the brake light. Is it lit up? If not, then your starter interlock isn't satisfied and the starter won't crank. It is not enough to just apply the brake. The brake switch has to work in order to supply 12 volts to the starter solenoid. The way to tell if the brake switch is actually working is to look at the brake light. (If you don't have a brake light then you'll need to use a meter to see if 12 volts makes it to the other side of the brake switch when applying the brakes).

2) Set all kill switches in the "run" position. Turn on the ignition switch. Put the quad in neutral and set the parking brake. Follow the big fat red wire from the battery down to the starter solenoid post. Follow the fat wire from the other post on the starter solenoid to the starter. Take a screwdriver and short those two posts on the solenoid to together (some sparks are OK). Does the starter turn, and does the quad start up?

You stated that the fuse was good because the battery had voltage. This does not follow. The way to check the fuse is to measure the voltage to ground on both sides of the fuse. If one side reads 12 volts and the other side reads 0 volts the fuse is bad. Since both battery power and ground connections go to the ignition switch, and since the internal tumbler on the old switch broke up, it is quite possible that the fuse got blown.

What color wires are there on the ignition switch? Use the wire colors in the main harness instead of the pigtail leads on the switch if they don't match. (I'm asking this in anticipation of the next tests to do if the above doesn't zero in on the problem).

 

hi thanks...I re hooked the battery up to my charger and ran a test it shows 13.7 is the reading its coming up with... I then rehooked up the battery and when I squeeze the brake handle the brake light still doesnt light up. I tried the screw driver on the starter terminals and nothing happened no, sparks nothing... I removed the fuse and did a visual inspection and couldnt see any signs that it was faulty(it is a glass tubular like buss fuse I believe) I then removed the top plastics so I could get a better visual of all the wiring and all plugs are firmly together... except where the wire comes from the spark plug to a black cylinder I see a black wire connected and a green wire hanging loose with solder on the end but couldnt see where it would have been hooked up? Could this be the issue? Thanks again for the assistance

 

13.7 volts is right on the mark for a battery that is being charged. Batteries by themselves have an output voltage that is set by chemistry laws. A fully charged six cell lead-acid battery has a voltage of 2.1 volts per cell - times 6 cells equal 12.6 volts. When you pull up the battery voltage higher with a charger then current flows backwards through the battery and charges it up. The right amount of charging current happens when the battery is held at 13.5 to 14.5 volts.

When you short the starter solenoid terminals you are hooking the battery up straight across the starter. The starter should turn no matter any switch position or safety interlock status. [That's why I had you set the parking brake and shift to neutral just in case it started up]. If you short the solenoid and the starter doesn't turn then it means one or more of the following:

1) The battery voltage can't put out enough current to run the starter motor and the battery voltage collapses to near zero. Put a meter directly across the battery terminals while shorting the solenoid. Does the battery voltage collapse, or stay above 11 volts? If the battery voltage collapses then jump the quad to your car and try again.

2) You have a bad connection in the fat heavy wiring down to the starter, and/or the fat heavy ground return path to the battery minus terminal. If you have 12 volts at the battery terminals while shorting the solenoid, but have zero volts at the starter (also while shorting across the solenoid) the there is a bad connection somewhere. Use the meter to find out where the wiring transitions from having battery voltage to having no voltage while jumping across the solenoid. If any connection gets hotter than other connections zero in in that point and look carefully right there.

3) You have a bad starter. If you have 12 volts across the starter (from the starter input post to the engine ground on the starter frame) and it doesn't turn then the starter is bad, unless...

4) The engine is frozen. This is very unlikely since you reported no sparks when jumping the solenoid. A stalled starter trying to turn a frozen engine draws lots of current and will definately make some sparks at the solenoid terminals.

Visual inspections are good most of the time but not always. But a blown fuse will not keep the starter motor from turning when you jump acroos the solenoid, so I'd start looking at that problem first.

Solve the starter turning problem first, then if necessary we can look into this problem further.