How to wire a reverse polarity switch

I have an old Rascal 600 scooter that has a seat actuator that will go up but not down. I have
tried to find the problem but can't.  It will operate up and down early in the morning when it is
cool but later after it warms up it will only go up. I want to wire a reverse polarity switch directly
from the 23VDC system(2-12 volt batteries)to the actuator motor. The actuator motor is 24VDC
12.5 AMP. It has a compression load of 600LBS. The motor has a black and red lead. Please
include the size or sizes of wire I will need.  Also please be as specific and simple as possible.
A drawing would be especially helpful. Thanks a million and God Bless!

bernie3084 years ago
You will need a DPDT(double pole double throw) switch with 3 positions. The switch should be (on) Off (on) (the "( )" means momentary).

Now you take your 2 motor wires and put them on the center 2 pins then your power supply (24 volts) will go to 2 pins on one side then reverse the power supply on the other side's 2 pins.

When you move the switch one way it will go in one direction and when you move the switch to the other position if will go the opposite direction.

Hope this helps.
Tomdf4 years ago
I think he is wanting to bypass the main switch by having a direct connection from the motor to the battery. That way he could guarantee that the motor is getting the reverse voltage to turn it the other way. Is that right, themanpan68?

IMO that would be a band-aid fix that may or may not produce the results you want, and it could potentially damage the circuitry. I suggest that you track down exactly why the motor won't go down when it warms up, it could be a mechanical problem rather than electrical.

Try this, get a digital multimeter, as mpilchfamily suggested, and touch the leads of your batteries. You should get around 24 volts. Next place the volt meter leads on the motor (black to black, red to red) and press "up" on your switch. The motor should move up and you should get around 24 volts on your meter. Now do the same thing, but press "down", this time you should get -24 volts on your meter. If you are getting the -24 than then motor is getting the voltage it needs and it may be a mechanical problem.

If you do not get -24 volts then it is an electrical problem, the next step would be to test the switch.
You don't need to go through all this trouble to test weather a switch is bad or not. All you need is a DMM and perform a continuity test on the switch. If you don't have a DMM it would be a good tool to have and you can pick up a cheap one for about $20 that will do what you need.