M.L. Toys
M.L. Toys
HobbyMasters M.L. Toys
I want to go faster.
Hello All! First off, I'm a newbie to modifying power wheels, but I love the idea, as I'm always tinkering. Glad I found this forum, but I can't find any help with the issue I'm having upgrading my son's BPRO from 6V to 12V, and its driving me nuts! :cry:

Here's the details:
It's a 6V Rollplay Chevy Silverado
I've added a 2nd gearbox (ordered it from Rollplay, so it's identical to the other one)
I've wired up a second identical stock 6V battery in series to boost it to 12V
I've swapped out the stock motors with the 12V Duratrax 550 starter box motors, that I've heard on here are good motors

Here's whats going on:
It works well for awhile, maybe 10 minutes or so, depending on how loaded the motors get (ie if he "offroads" it, etc). It goes fast when its working. I've checked, and the motors are receiving the 12V. After awhile though, it starts to sputter, the "on" button light flickers on and off, then it stops working. The batteries still have a full charge. After awhile, it will start working again.

So, based on this, I would guess something is overheating, but I don't know what. It's not motors, as they're 12V motors, I even put heat sinks on them. I feel the exposed wires, and they don't feel excessively warm, so I don't think its that. The truck does have a battery indicator board and a MP3/speaker board and headlights, which I thought may have been the issue, so I bypassed them by unplugging them, and its still having the same issue. The last thing I can think of is the motor control board which contains 2 relays and 2 resistors. Could this be the issue? Either that or some wiring is too small of a gauge and overheating and I'm not realizing it?

Any help or suggestions is MUCH appreciated, as again, its driving me nuts that I can't figure it out! I'm about to put it back to stock and sell it for a different one.

I'm not very familiar with that ride on and yes the relay board could very well be the issue. That ride on has a self resetting fuse in the harness. It could be tripping. What batteries are you using? Some batteries have a built in self resetting breaker. Sine it stops and then starts working again the thermal fuse would be suspect to me. They can be replaced with a slightly larger fuse.
Thank you so much for the suggestion!! That very well may be the problem, I was suspicious of those things but I couldn't figure out how to check them. They are the stock batteries. Where s the best place to get an inline fuse holder? And Ive heard a 30 amp blade fuse is the most appropriate?
Yes!!! That was it! Thank you SO MUCH for the help! Again, it was driving me nuts. I installed some inline 30 amp fuses from Walmart, and my son took a long ride and it never died! I think I also need to replace some of the wiring with thicker wire since it did get a bit warm but I'll do that later. Thanks again for the help!! Now he can leave all the neighbor kids in his dust!
OK, so I declared victory still a bit too soon. The truck runs for awhile, maybe 10-15 minutes, then will slowly lose steam to a crawl. Its still receiving power though. I replaced the battery wiring with 12 gauge braided wire. But the relays on the motor control board are getting quite hot. Do those need to be upgraded to relays that can handle 12v and 2 motors instead of the stock 1 motor?? I haven't read anything about replacing these so I am skeptical. I thought this was going to be easier to upgrade from 6v to 12!? Argh...
Ok, so got the new relays soldered onto the board and they were working great until... his 6 year old niece hopped in the truck with him and overloaded the system. It konked out and the relays got really hot. I'm thinking they may have been permanently damaged because he rode it two days later and it's now working intermittently and the relays are overheating. Do you think the relays have been blown? These are 12v relays, what kind should I get to prevent this from happening again? I can't keep having issues, my son, wife and myself are all getting very frustrated!
So the 12v PCB relays I first got were rated for 15a. I figured thatd be good enough but apparently I was wrong. So I just got some automotive 30a/40a relays, and they seem to be working pretty well, although I don't have a lot of time on them. We just got done using it for awhile, off and on for about 45 min, and it started to slow to a crawl yet again! I felt around for what might be getting hot, and the relays seemed fine, but now the motors seemed fairly warm. I checked the battery voltage and it was at ~11.95v, so it wasnt the batteries. These motors are the duratrax 550 starter box motors, which I've heard you don't want to run at voltages much greater than 12v. I know when my batteries are nearly fully charged, the motors getting closer to 13v, so could this be part of the problem?

Also, I tried out this voltage pulse width modulator I got off eBay for like $8, to be able to have the speed be adjustable. Well, it sort of worked... it did modulate the speed in the fwd direction, but reverse didn't work at all! In fact, in reverse, the only thing that happened was the headlights turned on! Also, in fwd, even with it turned all the way up the voltage to the motors topped out at 9.5v, so it wasn't going as fast as it could. Also, it caused it to coast to a stop. So... I removed it.
I believe I have the same power wheels role play model as you have. I have recently upgraded my son's battery with a 12v battery as well still using the stock motor. He has a similar issue where it will go great for about 10-15 minutes then shuts off. His has a led push button on/off the button will still be depressed with the led off. He can toggle the button a few times and it does come back on and will be sort of slow. I thought it was a connection issue as the terminals on the battery I bought were actually a tad smaller. Have you since found any solution for this? I also was very curious if you knew the pinion teeth count for the the pinion gear as you mentioned you replaced the motors..also how easy was it to add another gearbox to the other side? What gear box is it? Sorry for so many questions and not really any anwsers but hopefully you can at least help me out.
Honestly you should just bypass the board and run the 12v through a switch/relay and directly to the motors.

If you want keep a small 6v to run the board for effects. Sounds/Lights etc etc.

This is probably the easiest and less problematic way to get a solid 12v to your motors without dealing with the hassle of the PCB and additional relays
I have started the conversion process, added a second identical 6V battery in series. When I power on the car and it stays on for about 3 seconds. Suspected the thermal switch. Removed the thermal switch, no change. Removed the second battery, works fine. There is nothing on the main board except 2 diodes to restrict flow to one direction and 2 relays. Kind of a head scratcher as there are no switches in the circuit anymore to cut off power. Could be in the motor?
Hey guys, i just got a 6v rollplay mustang for my step son, im gonna wanna give it more power and speed 1 day for him. So what did you guys end up figuring out?

I was hoping to just buy another battery, wire it in series and call it a day with stock motor and such and the 1 wheel drive..

But reading this I may have to get creative... So what you all find out?
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