Burned up wire off solenoid

[RPMS949]

Need help figuring out what has caused this?
I believe that the motor is the cause?

[scottyb]

Good news - I believe you may have burnt up the solenoid, not the motor as we spoke about on the phone. That stud is black with heat discoloration... likely the small wire was an incidental casualty.

[JohnnieB]

Maybe not the solenoid either.

1. The stacking is wrong, backwards in fact.

The high current cable should go on the stud first, then the red wire, then the resistor.

The bulk of the total amperage for the drive system is (was) passing through the lightweight ring terminals to get to the solenoid contacts, so they got hot.

2. I also see that the lock washer at the very bottom of the stud, is not fully compressed. That might be more of a heat problem then the stacking order.

Between the two, the connections at that terminal were destined for excessive heat failure.

[scottyb]

There's history you should know - PDS -42v 4 passenger cart with 400 alltrax & stock motor, used for street transportation hauling beach gear up very steep hills. We are replacing the solenoid with the super-duty 400 solenoid to insure the highest amp handling capacity. Your stacking observation has been noted. The lock washer tension may have been relieved by the extreme temperature.

[JohnnieB]

Thanks for the background.

Hauling stuff up steep hills draws a lot of amps, regardless of motor type.

A Super-Duty solenoid ought to do the trick.

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Other places the staking order rears its ugly head is on battery studs and on the bus terminal on top of controllers.

Battery studs are the same as solenoid studs, the heaviest current carrying cables/wires go on first. If there are two high current cables on a bolt through bus terminal like those on top of a controller, put one on one side and the other on on the other side. (Sandwich the bus terminal between the cable lugs.)