I'm trying to refurbish a Razor E175. It sit in my shed for about a year and got wet at some point when the shed flooded. Of course it would not run so I began by using online sources to troubleshoot. The controller was not working so it opened it up and saw it had got wet and was badly corroded so I replaced it with a new one. The batteries seemed to be good, 26.5 volts after charge. The motor ran but I removed it anyway and took it apart to inspect. It had also got wet inside and was badly corroded. I cleaned it up, put it back together and it seems to run OK, directly from the batteries. The throttle and brake switch both checked out good with an ohm meter. The on/off switch and circuit breaker are also in good shape. So here's the problem: After replacing the controller, I turned the power on to see if it clicked when I turned the throttle, which it did. When I spun the wheel to simulate kick-start it ran the first few times but then would not start again. Also I could no longer hear the controller click. Turned the power switch off and back on and the controller started clicking again but the motor would not start up again. If I let It sit for a while I can get it to start once or twice but then it does the same thing again. Also when I turn the throttle to listen to the controller click it sounds like the relay engages but then trips. Can't figure out if I have a motor short or a battery short problem, or something else. Any ideas?
Chances are fairly high that the batteries are dropping too much Voltage under load which is causing the controller to shut down. If the batteries were in storage for around a year without being recharged then they experienced a significant amount of self discharging during that time which would have caused their lead plates to oxidize. This can cause their Voltage to be normal when not under load however drop when under load. The controller will click but not send power to the motor when the battery pack Voltage drops under 23 Volts, and if the Voltage drops even lower then the controller will not even click.
I recommend to test the battery pack Voltage when the scooter's power switch is on and the throttle is fully engaged. If the battery pack is good the Voltage will only drop a little, maybe 1/2 to 1 Volt or less. If the battery pack is not good then the Voltage will significantly drop by when the throttle is engaged. A drop under load to 23 Volts or less indicates that the battery pack needs to be replaced.
If the battery pack Voltage does not significantly drop under load then please let us know and we will take it from there. Please let us know if you have any questions.
Thanks a bunch! you are correct, the batteries dropped to about 22 volts when I turned throttle and the controller relay clicks but then trips again. I really appreciate you help.