EZGO TXT goes in rev when fwd selected.

[Retired70]

I am rebuilding a 2001 36 volt EZGO TXT series cart. This was an old service cart that I knew operated normally before being retired. I have replaced all cabling from the motor to the DCS and ESC as well as the battery cables. I also replaced the DCS with a heavy duty unit and the solenoid. Batteries are new.

Once assembled I function checked the cart and found that with the DCS select handle in fwd the cart runs in reverse. When reverse is selected the buzzer sounds but the cart does not move. You can hear the solenoid click when the accelerator is pressed.

I checked the wiring for obvious crossed wires and used a line drawing provided by a cart dealer. And everything is as it should be, per the drawing.
Example: S1 motor terminal to direction selector B.
S2 motor terminal to direction selector D.
A1 motor selector to controller M-.
A2 motor terminal to direction selector C.
With DCS positions as viewed from the back of the DCS being C at 12 o’clock, D at 3 o’clock, A at 6 o’clock and B at 9 o’clock.
Any ideas where to check next?

[scottyb]

Swap the 2 S cables S1 and S2 on the F&R to reverse the direction

[Retired70]

Already tried that and the cart didn’t move in either direction.

[Volt_Ampere]

You can reverse direction by switching either S1 and S2 or A1 and A2 at the motor. But what scottyb told you to do should have worked.

[Retired70]

At the motor? I’ll try that. When I swapped cables B and D it was on the directional switch. (S1 and S2) Is there circuitry within the motor or controller that makes the difference? The A1 cable runs to the M- connector on the controller and A2 runs to connector C on the directional switch.

[Volt_Ampere]

The controller does not know what direction the motor is turning. You can reverse the motor by either reversing the A1, A2 connections OR the S1, S2 connections. The Fwd/Rev switch does just that. It reverses S1 and S2.

[Retired70]

What role do the 2 micro switches play in the directional change? Changing the motor cables only changed the selector handle position that drives the cart in reverse. (Selector handle in fwd, cart goes in rev. Handle in rev, buzzer sounds but cart doesn’t move.) I found that a jumper bypassing the Reed switch was installed on one of the micro switches. It runs from a connector marked “normally closed” to the positive connector on the battery pack. I know this jumper will allow the cart to move if the Reed switch fails, but if I have a wire crossed will that effect the direction of travel? There are 4 connectors on the micro switches, any ideas which may be crossed?

[Retired70]

I swapped the blue wire on the micro switch with the black (jumper) wire and now the cart moves in the forward direction when selected but will not go in reverse. So now I’m convinced that the problem is in the wiring of the micro switches. And I also found that with the wires swapped the charging function no longer works. I am going to replace the charging connector and will eliminate the jumper wire. But which wires control reverse?

[Retired70]

Well it’s taken me a while but I finally got this cart on the road. The whole thing was giving me fits. I checked all the wiring again and again and finally I replaced the fwd/rev select switch. This switch was a new piece and because it is a simple mechanical switch I had resisted replacing it. But it was the only component that I hadn’t examined. I replaced it with an older one that I had rebuilt and it worked normally. The contacts one the first switch were good and making good contact with each other. The problem was in one of the micro switches.

In case you’re interested, you can by a replacement backing plate for the selector switch and transfer the other components over. Usually what happens is the contacts overheat and the backing plate melts and the contacts don’t connect. The contractor cam is usually undamaged so you can reuse it. The copper contacts are readily available. You can pick up a backing plate on ebay or Amazon for around $40.00. I’ve attached the correct wiring diagram for this model year “series” cart.