EzGo series TXT issues again

[MartinEZGo]

I've got a series TXT cart with 36v pack that will not move. Tested the motor with 12v and it works fine. It is the 1205 controller and it seems ok as well. 38v at the pack, fresh off the charger. F/R switch has power at all 4 connections. It has me scratching my head. Any fresh eyes willing to help me narrow this down?

[MartinEZGo]

It has the 1205-117 400amp Curtis controller as well. I think this may be the issue, but it seems to be showing power in all of the right places.

[Andy4639]

Jack the cart up and start by looking at the solenoid. Put meter on 36 ground of batteries and check the solenoid. Battery side first then move to controller side of it. What is the voltage at both. Then check it again with key on and G/P pressed enough to engage it see if it's passing voltage. Check the micro switch in the floor board also.

[MartinEZGo]

Key off, N position....pack side of solenoid reads 38.1v. Controller side reads 0v. Key on, F position.....pack side reads 38.1v. When pedal pressed, controller side reads 38.1 volts. Red wire to the small solenoid terminal from MS at the ITS reads 37.8 when pedal is pressed.

[MartinEZGo]

This is also a 36v TXT with the 4 blade controller

[JohnnieB]

Sounds like the solenoid clicks when pedal is pushed. If so, connect your DVM between the controller's B- and M- terminals.
Press pedal just far enough to make solenoid click and you ought to read full battery pack voltage (38.2V when fully charged).

If the voltage isn't there, leave the black test lead on the B- terminals and use attached schematic to go looking for the missing voltage, tracing the heavy cables step by step towards the battery pack's main positive terminal.

[MartinEZGo]

Johnnie, the solenoid does click, and tracing power back from B- and M- (which show pack at the solenoid click) shows power everywhere. All 4 motor posts have 37.8 volts, all 4 F/R posts have 37.8 volts and all B- combinations at the controller show 37.8 volts.

[JohnnieB]

Originally Posted by MartinEZGo

Johnnie, the solenoid does click, and tracing power back from B- and M- (which show pack at the solenoid click) shows power everywhere. All 4 motor posts have 37.8 volts, all 4 F/R posts have 37.8 volts and all B- combinations at the controller show 37.8 volts.

Good, that indicates the turned off MOSFETs in the controller is only open in the high amp circuit.

Now press pedal slowly to floor and the 37.8V between B- and M- should smoothly decrease to 0V, or very slightly above. If it doesn't, either the throttle circuit is bad or the controller is bad.

Has that controller ever worked in that cart? They are factory programmed for either a Pot-Box or an ITS for EZGO carts and the controller's throttle type has to match cart throttle type.

[MartinEZGo]

There is no fluctuation from 0 volts up until it clicks, then it reads pack voltage of 37.8v with no drop at all with pressing the pedal slowly to full throttle.

Yes sir, it worked before but the owner did say that it would randomly cut out from time to time. I have worked on it twice before and never got it to act up. But now it is totally dead.

[JohnnieB]

With DVM negative lead on B- at battery pack, measure voltage on Pin-3 (white wire) at the controller.

Should be form 1.4V to 1.8V when pedal is pushed just far enough to make solenoid click and from 2.4V to 2.8V when pedal is on floor.

Also, there is a 4-pin inline connector that connects the gray cable from the pedal box to the wiring harness that often gets corroded and causes all sorts of strange happenings. Best way to solve/prevent those issues is replace the connector with butt-splices or solder joints, covering either with marine grade (adhesive filled) shrink tubing.