24v DC reversible motor wiring

Discussion in 'General Electronics Chat' started by gatorsby7, Nov 1, 2011.

  1. gatorsby7

    Thread Starter New Member

    Nov 1, 2011
    i have a mobility scooter (JP Cruiser - HCF305) that has a 24v motor with four wires. Two heavy gauge wires, one red, one black. and two light gauge one red, one black. the scooter has a forward, neutral, reverse (F-N-R)switch that i think is broke. the motor only runs one direction. the F-N-R switch routes thru an electric controller box. the 4 wires to the motor come out of the controller. my question is what do the motors 4 wires do? FYI, the F-R-N switch is 3 wires to the controller. the switch also has a hot wire from the key switch. what do the F-R-N 3 wires do? thanks for your help, i need to get my mobility back.
  2. jimkeith

    Well-Known Member

    Oct 26, 2011
    This motor is probably a shunt field DC motor--two light gauge field wires and two heavy armature wires--direction can be easily reversed by swapping either the field or armature wires. The controller probably PWMs the armature to produce variable voltage (speed).

    On the FRN switch, it likely energizes one of two (2) pole relays that connect the field winding in either polarity. Field windings have high energy storage and cause relay contacts to arc and deteriorate. My best guess is that you have a bad relay--or as you said a bad switch.

    Hope this is helpful.

    From the voice of ignorance--never having worked on one of these.

    I did a 5 minute google search on this, and did not turn up any useful info.

    Check out these links--you may be able to pick someone's brain there, and they have a forum that may be useful. http://www.monsterscooterparts.com/mobility.html


    Do not check out this link: http://off2dr.com/modules/cjaycontent/index.php?id=16
    Last edited: Nov 2, 2011
  3. gatorsby7

    Thread Starter New Member

    Nov 1, 2011
    thanks for the reply jimkeith,

    i too had searched the internet but not found the info i needed. but your reply got me thinking (that's dangerous).

    i think the FRN switch is bad (as opposed to something in the controller)because somebody spun it around past its normal limit of travel. when i move the switch it doesn't look like the contacts on it line up with where i think they should be. i'm having difficulty getting it apart to see if i can "fix" it. i say fix that way because i don't really know how it works. after reading your response, i now think it is just a 12v polarity reversing switch. if i can't fix it, i see their are cheap ones on ebay that i could maybe try.

    i have a multimeter, and confirmed that the hot wire from the key to the switch is indeed 12v. now if i can just learn how to determine polarity so i can test/fool with it.
  4. gatorsby7

    Thread Starter New Member

    Nov 1, 2011
    i have not had any success testing/fixing the FRN switch. I did learn more about the motor though. I tried reversing the two light gauge wires to change polarity in hopes of reversing motor...but it still ran same direction. I then reversed the heavy gauge wires and the motor reversed. i found the voltage to the heavy gauge wires varied with throttle, and the voltage at the light gauge remained constant (about -3.93v).

    the FRN switch has the red hot wire to it, and 3 wires (black,blue,lt green) going to the controller. moving the switch makes no change in motor, and motor runs even with switch disconnectd. when rotating switch, the only reading i can get is 12v on black when switch is on Neutral. no readings on blue or green. i'm lost.....
  5. franlee

    New Member

    Nov 2, 2011
    hello. if that is a shunt wound motor, which i believe there's no brushes, the thicker gauges wires are the main field wires and the thinner gauge wires are normally the reversing wires. your line will be 1 heavy gauge and 1 smaller gauge on each line. to reverse just switch the position of the smaller gauge wires. try a lower voltage like 12vdc just to be on the safe side not to burnt the windings and tap connect only not cap connect. also with dc voltage, reversing polarity would also reverse the rotation. hope it helps you.