2004 TXT electrical problems / short

[radioman]

There appears to be a problem with the motor. While you got it out verify there is an open between A1 and A2 with a ohm meter. If there is open circuit the motor is going to need to be serviced or repaired. Like yurtle said it might be the brushes.

The other things you are going to need to check/repair is the circuits switches that was damaged with the shorted diode from installing it backwards. You can do this with a voltmeter measuring referenced from battery negative (put the negative lead on battery -). The places you need to check for voltage are as follows. Battery + voltage at the small white wire at the charger receptacle (originates through the reed switch from positive in the charger recept), with the forward rev switch in position this voltage continues through a micro switch on this assembly, next to the key switch through a blue wire, out of key switch on a green wire to another micro switch in the pedal box that closes when the pedal is depressed and then to the side of the solenoid coil with the red wires where you had the shorted diode. All of these items have to operate to get voltage to energize the solenoid. They are all connected in series.

Make sure you understand how to read an ohm meter checking the motor and post the exact ohm readings. S1 and S2 are called the field coils. A1 and A2 are called the armature connections (yurtle already covered this but here it is again) Both have relatively low resistance readings but I don't know the exact readings. No reading between S and A terminals is a good sign. A good thing to get familiar with reading ohms is to get a regular light bulb and measure the resistance. No reading between the A terminals indicate a problem inside the motor.

With the shorted diode removed you should be able to continue working getting the solenoid to energize in a smoke free environment. Protect cart from unexpected movement. With motor out it will not likely move.

[RSGreen]

I really didn't pay close attention to the range; good point. I just went and re-checked it on all the different ohm ranges and it reads the same - 0 between the two S's and 1. between the A's.
... and 1. between any of the S's and A's

[RSGreen]

radioman: thanks for the reply. Got voltage at all the spots you indicated in your post and with the diode still removed turned the key and pressed the pedal. The solenoid did click loudly so I think that circuit is good. Checked the motor resistance again and got the exact same readings: 0.0 between the field coils and 1.0 between the armature. Just to make sure my meter wasn't faulty I checked a 100w standard light bulb like you suggested and got 9.7 ohms of resistance on the 200 ohm scale - which is the lowest scale available on this digital multi-meter.

[yurtle]

Originally Posted by RSGreen

I really didn't pay close attention to the range; good point. I just went and re-checked it on all the different ohm ranges and it reads the same - 0 between the two S's and 1. between the A's.
... and 1. between any of the S's and A's

New info. I thought you had no continuity between As and Ss. This could be BAD.

[yurtle]

1 Ohm between an A and an S, with all cables disconnected is a dead short. Possibly damage when removing cables.

[RSGreen]

yurtle: maybe I'm saying it wrong or reading it wrong - but the way this digital meter reads - when on the ohms settings - if you short the leads together it counts down quickly from 1. to 0.00 Then if the leads are not touching anything (just hanging in the air) it reads 1.0 again. Is there something wrong with the meter ...or more likely the operator?

[radioman]

Originally Posted by RSGreen

yurtle: maybe I'm saying it wrong or reading it wrong - but the way this digital meter reads - when on the ohms settings - if you short the leads together it counts down quickly from 1. to 0.00 Then if the leads are not touching anything (just hanging in the air) it reads 1.0 again. Is there something wrong with the meter ...or more likely the operator?

This is what you reported in your first post

"I disconnected all wires to the motor and checked continuity. I only have continuity between F1 and F2 but NOT between A1 and A2 and not between any of the A and F terminals. Perhaps a bad motor?
Greatly appreciate any advice or testing I can perform to get it running again.

Has this changed?
Since you are getting more familiar with the workings double check this again. Cause the present readings indicate trouble with the motor innards. I think your meter is playing tricks on you if you are reading 1 with the leads in thin air and the reading between A & S terminals may be a ghost reading. See if you can borrow or buy a better meter you can trust. You need one with a R x 1 scale on it. Good you got the solenoid to click. Your motor just might be ok or the A terminals might be open since meter reads a 1 in thin air. Before I would put it back in the cart to try you got to verify the ohm readings. Digital meters can mislead you if not careful. They will pick up stray static electricity when the leads are just hanging.

[radioman]

I am trying to come up with another simple way to see if the A terminals are really open or not.

This test is to be conducted with motor out of cart.

If you have some clip leads to make some temporary connections from a battery positive to the motor A2. Connect the other jumper to the A1 terminal then through the 100 light bulb (you used to check the resistance) return to the negative post on same battery.

Then connect meter set to read voltage put negative lead on minus battery and read voltage with pos meter lead on A2 terminal with light bulb connected. If you get no voltage the A2 terminal armature circuit is open. As long as the motor is isolated you can clip any battery in the bank for voltage source. You do not have to disconnect battery from the bank. If you don't feel comfortable doing this then don't. I don't know what voltage you would get on A2 but I would expect a few volts.

[yurtle]

If this is a series motor, connect any A to any F and apply 12 to 18 volts to the other two terminals up on jack stands. You'll know pretty quickly if it works. Reverse the voltage and it will spin the opposite direction. ONLY for series motors.

[radioman]

Originally Posted by yurtle

If this is a series motor, connect any A to any F and apply 12 to 18 volts to the other two terminals up on jack stands. You'll know pretty quickly if it works. Reverse the voltage and it will spin the opposite direction. ONLY for series motors.

That test is a good one but I think the motor needs to be in cart for a load. I think he has it out of the cart.