91 Marathon suddenly stopped running

[Racerjoe56]

1991 Marathon 36 volt cart has been running great but my wife went to drive it and got about 15 feet and had to let off the go pedal to ease passed the dog and when she pushed it again it would not go.

just happened maybe an hour ago and we had to leave until tonight.

One thing I noticed was that the 250 ohm resistor on the solenoid between the two big lugs was hot enough to burn my finger

what would/could cause the resistor to heat up that much?

any ideas?
Thanks
Les

[JohnnieB]

Either the solenoid's contacts are not closing when the pedal is pushed, or the contacts are so badly arced they won't pass amps all the amps the motor is calling for.

Basically, the motor is trying to draw a couple hundred amps through a 270Ω - 10W resistor, so it gets mighty hot mighty quick.

[Racerjoe56]

Originally Posted by JohnnieB

Either the solenoid's contacts are not closing when the pedal is pushed, or the contacts are so badly arced they won't pass amps all the amps the motor is calling for.

Basically, the motor is trying to draw a couple hundred amps through a 270Ω - 10W resistor, so it gets mighty hot mighty quick.

So either one of these indicate a bad solenoid? I was planning to find a solenoid test procedure on here tonight and check it tomorrow.... the solenoid is clicking when go pedal is pushed.

Sounds like it most likely needs one.... correct?

Thank man

[JohnnieB]

Originally Posted by Racerjoe56

So either one of these indicate a bad solenoid? I was planning to find a solenoid test procedure on here tonight and check it tomorrow.... the solenoid is clicking when go pedal is pushed.

Sounds like it most likely needs one.... correct?

Thank man

If the solenoid is clicking when the pedal is pushed and the resistor is getting hot, the solinoid contacts are not passing amps like they are supposed to, so the answer is to replace the solenoid with a good one. It would be a good time to upgrade to a 200A (or more) solenoid.

[Racerjoe56]

Thank you

[Racerjoe56]

I replaced the solenoid with a 400a.
No difference... push go pedal and nothing happens.
I had another guy telling me with much conviction that my problem was in the solenoid....’ I am kinda at a loss right now but I figure that my next move will be the controller.

Can anyone take a look at this image and tell me who this girl is.

Thanks
Les

[Racerjoe56]

[QUOTE=Racerjoe56;1757682]I replaced the solenoid with a 400a.
No difference... push go pedal and nothing happens.
I had another guy telling me with much conviction that my problem was in the solenoid....’ I am kinda at a loss right now but I figure that my next move will be the controller.

Can anyone take a look at this image and tell me if these wires are wired correctly..... diode direction, yellow and black wires...etc.??

I hope this attaches the picture of the solenoid..


Thanks
Les

[Mooncarter]

Is the new one clicking?

[Racerjoe56]

That was meant to say that I had another guy tell me with much conviction that it was my controller .... I tried the solenoid first based on the comments above (and obviously the cost factor).... so if you guys tell me this looks wired correctly I guess the only thing left is the controller. (If so I will replace the cables to a 2 gauge as I can see most of you guys do that when going to higher amp controller)
Thanks for any input on the wiring in the picture

[Racerjoe56]

Originally Posted by Mooncarter

Is the new one clicking?

Yes sir... clicks every time pedal is pushed and every time it is released