My son has a Razor E300 scooter. The run time started to get shorter and shorter until it didn't run at all. I replaced the batteries but it still doesn't work. I can hear two clicks from the speed controller when I throttle up. The clicks are about a second apart. The batteries read around 26 V. I disconnected the brake switch but no difference. The motor seems to be an open circuit when I ohm it out from the connector. (Is this normal?) If I look at the voltage on the controller side of the motor connector, as I throttle up it goes from around 23 V (first click), and then drops quickly to around 1.5 V (second click). I'm not 100% confident that the batteries are good, except that they're new and the voltage seems reasonable but maybe a bit low. I'm worried that either the controller is bad, or the motor is bad, or that there's an open circuit in the motor cable. Any tips on narrowing this down?
I would start with testing the Voltage of the battery pack when it is under load to see if its Voltage is dropping too low. To do this test connect the multimeter to the battery pack and read the Voltage with the power switch on, and then keep looking at the multimeter as you twist the throttle and see if the Voltage drops when the throttle is twisted. A good battery pack will only drop around a half to one Volt during this test, while a bad battery pack will drop to under 23 Volts while under load. If the battery pack drops to under 23 Volts during this test then one or more of the batteries is bad.
The controller shuts down power to the motor when it detects that the battery pack is at 22 Volt or less. It does this to protect the battery pack from being over-discharged which would damage the batteries.
If the battery pack Voltage does not drop too much when under load then the problem could be the controller or motor.
Please let us know how it goes.
Thanks. I tried the test that you suggested. The battery voltage stays at 26.5 volts while turning the throttle. It doesn't seem to drop at all. I also took a snapshot of the controller output as I turned the throttle (attached). The motor voltage at the connector increases to around 20 volts for just under a second, and then it drops back down.
If you have not already done so I would test the motor by wiring it directly to a battery to see if it works. If the motor works, and the controller is clicking when the throttle is engaged, and the battery pack Voltage is not dropping to less than 23 Volts while under load, then that points towards the controller as being the problem.
Earlier, I checked the motor with an ohmmeter on the connector. It was an open circuit. I'm up for swapping out the motor. Can you recommend a part?
Another quick question: how do I remove the cable from the old motor? It passes through a grommet that's too narrow to accommodate the molex-style connector.
The connector is attached to the motor's wires after they are routed through the grommet so the terminals would need to be removed from the connector in order to get them back through the grommet. There is a locking tab on the terminal that can be pushed in with a mini screwdriver and then the terminal can be pulled out of the back of the connector. The locking tab can be restored back to its original position before reinstalling it into the connector.
We have two identical motors which are for the Razor E300 scooter. One of these motors is our item number MOT-E300 which is sold on the Razor E300 parts page, however it is currently out of stock. The second motor is our item number MOT-24250X2650 which is in stock.
Please let us know if you have any questions.
I received the new motor over the weekend and the scooter is fixed! The new motor was a little bit different from the original. The holes in the original bracket were countersunk, but the holes in the new bracket weren't. The cable from the motor was a bit shorter than the original one. But I was able to use the original mounting screws and run the cable over the batteries. The deck seems to be flexible enough to allow for the slight height increase due to the screw heads and cable.
Once I had the new motor in, I took the old one apart. I found some debris that looked like it had once been a sealant. There was a fare amount of corrosion and some heat damage on a couple of the wires. There are four brushes in this motor -- I assume this is to help get going from a dead stop. Two of the brushes had failed. This made me remember that when my son first noticed something wrong, he would push the scooter and it would start going. I suppose that one pair of brushes had failed at this point. This may have overloaded the other pair (the heat damage) until they failed too.
Anyway, thanks for your help. Your diagnosis was right on the money!
Sorry for the late response. Unfortunately I tossed the motor once I got the new one. I attached a couple of images of the installed replacement motor. It's possible that the cable is the right length, but it might come out of the motor housing at a different angle. Hope this helps.