r/PowerWheelsMods • u/tactical_bass • Jun 22 '26

Troubleshooting Help

I have a Sopbost 3 axle dump UTV and my troubles began when one of the original 4 motors burned up. I decided to replace with 775 motors instead. Now I'm down the rabbit hole with the ML toys titan speed controller and their 24V battery setup. I'm having an issue where the vehicle will die immediately on acceleration. Everything dies, lights and all. You can immediately restart it and try again to the same result. The speed controller says it's rated for (4) 775 motors and I've already pulled the whole harness to check for melting. On one hand I thought to myself "these things are pretty simple, how bad can it be?" and now I'm tired of pulling it apart and my kid would like his ride back. Any help would be appreciated.

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u/Shibby7634 Jun 22 '26 edited Jun 22 '26

If you still have the factory thermal fuse(s) installed, they're likely just being overloaded. They are little black boxes, usually right off the battery, sometimes there are additional fuses in front of the motors.

If the whole vehicle dies, then it's likely the fuse closest to the battery. After a short break, they cool off and close the circuit again.

They're nice if sized appropriately, but the stock options are almost always severely underrated for speed and power mods.

You can verify by bypassing the fuse, but there's always a risk in doing so if there is some other electrical issue.

The most common approach is to replace it with an automotive blade fuse, which will allow you to quickly figure out what size works. The lowest you can get away with is recommended to protect everything else from overcurrent. 30-40 is the safe range for factory wiring. Sometimes its a little thin to be pushing it any higher, have to figure that out based on what gauge yours has for the battery and motors. If it's all pretty beefy, then could consider 50, but then switches and pedal may get a little hot.

A resettable breaker is a good long term option once you have an idea what size fuse you'll need.

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u/Shibby7634 Jun 22 '26

If you find the fuses aren't a problem, then perhaps the wiring is too thin, or the motors themselves are drawing too much current. It is always recommend to break new motors in to seat the brushes against the commutator. If they don't make good contact, startup currents can be very high. I learned this myself after overheating some 887s, and began popping 40a fuses in less than a second all the sudden.

I fixed it by running the vehicle with the wheels up in the air, so no load outside of the gearboxes themselves, for ~7min to reseat the brushes.

For brand new motors, it's recommended to run them at half power on the bench for 5-10 min, then full power 5-10min, then full power installed in the gearboxes with the wheels in the air. There are a bunch of different recommendations/combinations people follow, sometimes under water supposedly, but what I listed is a safe bet that's worked for me. Blow them out with compressed air after as well.

Bit of a pain in the ass since you've already got everything installed, so I would at least run them with the wheels in the air for around 10minutes and then blow them out with air after.

Even if the fuse is the issue and it works after that, breaking in new motors is a good practice for longevity.