Rear steer killing SCX24 ESC

[Jeffh555]

I have a SCX24 JLU with the V2 electronics that I’m swapping to a Injora buggy with 4 wheel steering.

When I tore it down, it had a dead motor from 5 year olds abusing it. I.e. holding it in place to do 4 wheel burnouts in dirt.

Got it all together with a new Injora motor, and everything works except it only goes backwards.

After some research I concluded that my ESC was bad. I figured it was from the kids abusing it. The motor was really crunchy, and I wouldn’t be surprised if they held the throttle down after the motor went and the current caused the ESC to die.

I ordered a new stock ESC/receiver combo. While waiting for it, my buddy leant me his spare V2 ESC/receiver, he gave me the transmitter with it. Plugged everything in and the same thing happens, no reverse.

I have a spare motor and an entire spare SCX24. These ESCs won’t spin any motor both directions. The one good ESC will spin the spare both directions. Any transmitter acts the same with either of the bad ESCs.

Pulled the bad ESCs out of the case, and can’t find any components that are melted or otherwise look failed. Never got any smoke or bad smells.

Is plugging the Emax servo into channel 3 killing my ESC? I’m scared to try the remaining good ESC that I have. Steering works as it should.

Is the new Injora brushed motor somehow killing the forward circuit in the ESC, but not reverse? I'm also scared to try the new motor in the remaining good ESC.

Thanks for any help,

Jeff

 

[SLOWPOKE693]

Are they definitely dead or are you just assuming so? I had a bad two speed shift servo in my Bomber running all factory electronics and it did exactly what you are describing. Id try unplugging one servo at a time and testing functions and see what happens.

 

[Jeffh555]

I suppose I don't know that they're dead.

I have unplugged everything, just plugged back in the battery and a spare motor, and it only spins backwards, forward throttle does nothing. Paired to different transmitter (that works fine on my son's SCX24) and it does the same thing. This is the case for both "bad" ESCs.

The spare motor spins forward and backward when plugged into my son's SCX24.

I now have 2 theories.

1. The motor installed in my buggy is bad and pulling too much current. connected it directly to a battery and it spins both directions. I put a cheap china multimeter in line and it pulls .37-.38A in both directions. This is spinning the whole drivetrain in the air. I doubt this is the issue.

2. The rear steer servo is bad. I don’t know how to test this. It will pull .72A at one direction steering lock, but nothing the opposite direction. The specs for the servo (emax ES08MAII) state its max current is .9A.

I’m still at a loss. New ESC will be here tomorrow. I really don’t want to fry it.