Electrical issue I cant solve

[eduardo larson]

Hello all,
After pouring over the forums and finding great information and testing procedures i am still at a loss. I have a ezgo txt series cart with the 4 blade controller. Curtis model 1205-117. The cart was running then melted some batteries terminals. So we put 6 new batteries in it. We also noted that the F&R was looking a little hot. So we replaced the f&R with a brand new unit. The cart still did not run. After looking at the troubleshooting stickies we tested the solenoid. It was not working, welded shut. We replaced the solenoid, resistor, and diode. Still nothing. so we went back and tested the input side. Solenoid clicks and voltage pass from lug to lug. We borrowed a controller and motor from a running cart. My components ran on that cart, but my cart did not run with the components from the loaner cart. We checked and rechecked the wiring to make sure it was wired right from controller to motor to f&r. With both controllers installed and both motors, the cart just jolts a little like it wants to move but doesn't. We tested the ITS but the testing procedure we found here was the newer style controller. Is the test procedure similar to the 4 blade controller? I'm thinking the problem is with the ITS but I can't find a testing procedure for the 4 blade controller. I think at this point that's all that is left that is not new. I got proper pack voltage at my batteries, at the solenoid, it clicks, I know the controller and motor are both working on the loaner cart runs fine with my components installed. Can anyone shed any light or am i overlooking something? Any help and ideas would be appreciated.

[DaveTM]

With your cart up on jack stands, and being extremely careful...(you may consider removing your rear wheels\tires) use your Multimeter at the motor to see if you are getting power to the actual motor studs. Now, should the motor (for some reason, known or unknown) begin to work.....DO NOT let the motor spin at a full throttle. Why? Because you will likely let the motor spin above it's RPM limit and cause said motor to "fly apart" and break.

If you do not get power readings at the motor, then you have a problem at either the F\R switch, or the controller. If you have the proper power readings at the motor, then you likely have a motor problem.

Anyway.....in my tiny grey matter.....this is how I "confront" and attack problems and run down where they exist.

[Sir Nuke]

But Dave....he took his motor and controller out of his cart....put them in the known working cart and BOTH worked fine.....put them back in, and the problem still exists.

[eduardo larson]

That is correct Sir Nuke. the motor and controller both ran in the cart we removed them from but not in mine. My original motor and controller ran in the donor cart as well.

[JohnnieB]

The solenoid clicks, so the control wiring is good.
Your cart's swapped motor and controller worked in another cart, but motor and controller from other cart didn't work in your cart.
That leaves the F/R switch assembly, ITS and some of the high current cables.

Attached is a service manual for an industrial 875 series cart. Different body style, but same drive system you have in you TXT-HD cart, so the schematics and ITS checks ought to be the same for your cart.

However, unless the pedal box under the floorboard got wet, I'm more inclined to believe a bad F/R switch or a bad high current cable.

Put rear of cart on jackstands.
Connect your DVM between the B- and M- on the controller.
Press just far enough to make solenoid click and you ought to read full battery pack voltage (38.2V when fully charged)

If you don't get it, trace the high current cables to/from F/R switch and motor until you find it.

[eduardo larson]

Thanks, Jonnie B ill look at that tonight. I was pretty confident that a brand new F&R switch was not the culprit but I'll double check it. A bought a complete 4 gauge cable set and replaced all cables with new 4 gauge wires. batteries, F&R, motor. I'll triple check all my connections and placement on those again as well.

[Gregorio]

You melted battery terminal but did you replace the cables? They might not be the reason the cart doesn't run today but if they were not replaced, they could be a source of high resistance and trouble tomorrow

Good luck. Hope you get rolling soon!

[eduardo larson]

Yes we replaced all cables on the cart with a 4 gauge kit when we replaced the batteries and F&R

[Gregorio]

Originally Posted by eduardo larson

Yes we replaced all cables on the cart with a 4 gauge kit when we replaced the batteries and F&R

[JohnnieB]

New doesn't equal good.