Gruber
HobbyMasters
M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
for 12v vehicles that NEED to be upgraded to 18v
By Duhst
#150410
Hello!

Upgrading my daughter's Dune race to 18v. I purchased a 18v battery from Juice Box (12v+6v batteries) and also purchased an adapter for the stock Power Wheel battery to pos/neg wires for the new one.

My question is the adapter has a 40amp inline fuse and everytime I hook the 18v battery to the racer and press the peddle it instantly blows the fuse.. Jump wire from negative of 6 volt battery to positive of 12volt battery then negative of power wheel to negative of 12volt battery and positive of power wheel to positive of 6 volt.

Am I reverse something? Wiring issue? Do I need to rewire it? Help?


User avatar
By Hammer-fm
#150412
Your description of the wiring sounds fine. I would not expect 40A fuses to blow without any load unless they gave you fast-blow fuses (which would be odd).

Did you try it in '1' or 'R' (where the motors are in series)? That will present a much smaller load to the battery. Does it work correctly with just the 12V battery connected?

Have you done any other rewiring on the vehicle? If, for instance, the gas pedal connections get reversed, it will result in a short when you push the pedal and will blow fuses (i've done this at 2am before).
By Duhst
#150414
I picked up the dude race from a local thrift shop with no battery but I assumed that was the only thing wrong... I haven't done anything to it other than paint it.

When they sent the batteries they also sent four 40A fuses.

1st fuse - 18v, installed everything correctly blew fuse in 1 gear when gas was pressed.
2nd fuse - 12v only, blew fuse in 1 gear when gas was pressed.
3rd fuse - 6v only, took about one full second after pressing the gas for the fuse to blow.
4th fuse - I took a shot in the dark and reversed the jump wire on the 2 batteries and blew the fuse as soon as I pressed the gas.

I haven't touched any of the stock wiring in the racer but I'm completely open to the idea just have no idea where to start looking for a short or some wiring issue..
User avatar
By Hammer-fm
#150415
If this shifter is in the middle ('1st gear forward' -- which places the two motors in series) and it blow at 6V, then it's almost certainly a wiring short at the gas pedal or at the shifter itself. Both motors would have to be shorted out for a motor failure to cause that.

If you had it all the way forward ('2nd gear'), then it could be a blown motor but still fairly unlikely. Nothing moved when you pressed the pedal, right?

I would recommend taking it apart and tracing out the connections to the pedal and to the shifter, and compare against the wiring diagrams (there is a sticky thread for that).
By Duhst
#150416
Well darn...... Like you said 2am does weird things to you, haha! I was testing the battery while in 2nd (all the way forward) the whole time!

With that said... Would that just mean blown motor or motors? Nothing moved at all when I pressed the gas just an instant pop of the fuse.

I'm going to swing by and pick up some more 40A fuses tomorrow and test again in 1st (middle position).
By Duhst
#150417
Found a couple 30A fuses laying around and decided to try with those and still blew..

1st gear with 18v, blew
Reverse with just the 6v, blew

Haha.... I think I'm taking this thing apart! Any idea on where to start looking for motor(s) or gearbox?
User avatar
By Hammer-fm
#150419
I don't think your problem is the gearboxes or motors and I wouldn't order them until you know they're the problem. The results in 1st/reverse suggest that the problem is further upstream -- at the shifter or at the pedal.

Simply reversing the pedal connections is enough to cause the problem you are seeing -- and who knows what the previous owner did.

At the very least I would recommend taking it apart and disconnecting the motors (cut the wires and make sure they're not touching) and then try again. If it still blows then you know for sure it's not the motors.
By Duhst
#150431
Had some time to take the racer apart today and I'm not sure how the wires could get crossed up? Maybe I'm just not understanding.... Hahah either way, I attached some pictures of how the wires are currently set up.

Gas pedal
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Gear box
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User avatar
By Hammer-fm
#150433
Yup. When I said "If, for instance, the gas pedal connections get reversed, it will result in a short when you push the pedal and will blow fuses (i've done this at 2am before)." -- this is EXACTLY what i was talking about. I had taken the wires out of this connector and reversed the red & orange wires when I put them back into the plastic holder. This results in a hard short between B+ and B- when you push on the gas pedal.

Switch them back, just like the MLTOYS picture has, and you'll probably solve your problem. A screwdriver may be required to unclip the spade connectors from the plastic shroud, but it should be a <1min fix! Hopefully that's the only thing going on :lol:
By Duhst
#150437
Well gentlemen... I can't thank you enough!

Swapped the red/orange wires, connected the full 18v (12+6v) battery and bingo, bongo, bango! She's up and running! darn near gave me a heart attack when I pressed the pedal! Lol I didn't think to lift the back tires up and the darn thing jumped across the garage! I tired 1st, 2nd and reverse and everything works perfect!

MLToys, I'll give this a few test runs but I'll most likely be ordering the break reduction module you linked. Thanks for that!

Hammer, you're a legend in my book! When we bought it for $20 I didn't have high hopes! $60 battery and a few fuses later and it's good as new! Thanks a million!

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