Solenoid works,Cart don't

[JohnnieB]

Verify that you get full pack voltage (44.4V) between the B- and B+ terminals on the controller after the solenoid clicks.

What is the voltage between B- and B+ on controller when cart is running at top speed?

Check the ITS input to the controller. (Measure between Pin-1 and Pin-2 with everything connected)
Should be 10V when pedal is pushed just far enough to make solenoid click and 6V when pedal is on floor.

Verify controller settings.

Anything getting Hot?


Measure voltage between M- and B+ terminals on the controller. Should be the same as pack voltage when pedal is on floor.

I've got some Honey-Do stuff to take care of, but I'll be back later (hopefully)

[devybob]

O.K. voltage between B-and B+ is 44.4 volts**** B- and B+ at full throttle is 43.8volts****Measurement between 1 and 2 is 8.6 volts with or without engaging the throttle and 5.2 volts when fully floored.(problem?) Voltage between M- and B+ when fully floored is 12.50 to 13.00 fluctuating voltage.(big problem?) By the way whenever I take readings they seem to move up and down a little.

[JohnnieB]

The ITS voltage is wrong and the voltage going to the armature (M- to B+) is way low. The ITS issue may be causing the low output from the controller.

Disconnect J-4 (4-pin connector from the pedal box) at the PDS to DCX adapter and measure the voltage between Pins 1&2 with it disconnected and controller powered up.

I'm pretty sure it should be 10V, but call Alltrax if it if you get something other than 10V.

[JohnnieB]

Also, verify you have full pack voltage on controller Pins 9 & 10.

(That feeds the regulated power supply that feeds the ITS circuitry)

[devybob]

Between pin 1 an2 I have 14.02 volts and I have about 19 volts on pins 9 and 10 . Again tough to get reading because voltage meter fluctuates a bit.

[devybob]

I called alltrax and was told that 14 volts is OK between pins 1 & 2 he had me check the voltage at M- and B- at full throttle and was told it should read full pack voltage, however it does not. I get a reading of about 19 volts. The conversation ended there and I get the feeling he's looking at a bad motor. I'm almost afraid to call him back as I really don't want any more bad news. Anything else I can look for?

[JohnnieB]

Originally Posted by devybob

1. Between pin 1 an2 I have 14.02 volts

2. and I have about 19 volts on pins 9 and 10 .

3. Again tough to get reading because voltage meter fluctuates a bit.

Originally Posted by devybob

4. I called alltrax and was told that 14 volts is OK between pins 1 & 2

5. he had me check the voltage at M- and B- at full throttle and was told it should read full pack voltage, however it does not. I get a reading of about 19 volts.

6. The conversation ended there and I get the feeling he's looking at a bad motor. I'm almost afraid to call him back as I really don't want any more bad news.

7. Anything else I can look for?

1 and 4. 14V open circuit confirmed by Alltrax.

2. Should be full pack voltage (44.4V)
Attached are schematics with electrical paths to Pins 9 & 10 from their respective voltage sources.

3. Try replacing battery in your handheld DVM, or replace the DVM. The voltage readings ought to be steady as a rock on Pins 9 & 10.

5. The test points and the expected results are mixed up.
The test points are B- to M-. This will give you a positive voltage reading while going from M- to B- will give you a negative voltage reading. This is a minor point since the numbers will be the same except for the polarity sign, but we try to stay with positive voltages readings so people that don't understand polarity don't get as confused.

The expected results between B- to M- is full pack voltage (44.4V) with pedal up and 0.0V with pedal on floor.

On the other hand, the expected results when you measure between M- and B+ is 0.0V with pedal up and full pack voltage (44.4) with pedal on floor.

Since you only got 19V with pedal on floor, you didn't get the expected results for either set of test points, so something is amiss and more troubleshooting is needed.

6. It is too early in the troubleshooting process to determine if the motor is good or bad, or if the controller is good or bad, or if the ITS sensor is good or bad, or if anything else is good or bad. So far, we've conditionally eliminated the Keyswitch, the pedal switch, the F/R switch and the solenoid coil, but not the solenoid high current contacts.

7.a. Get a handheld DVM that works right.
7.b. Get full pack voltage on Pins 9 & 10.
7.c. Measure from B- to M- when the pedal is pushed just far enough for solenoid to click, once the controllers electronics are being supplied with the proper voltage.

If you do not get full pack voltage (44.4V), or mighty close to it, then the problem might be the motor, or the solenoid contacts, or one (or more) of the ten high current cables and their connections.

[devybob]

First of all I took some time to check all the cables, found a cable that went to the motor that looked like it had corrosion on in so I just had a new cable made up and installed it then repaired any wire that was not looking up to par.. No change! Next I went thru johnnyb,s list and here are the results:

I have a new DVM and an old working one and they both give me the same readings I have full pack voltage on pins 9 and 10 :: Black to neg battery post and red to pin 9 and the same for pin 10
Next measuring B- to M- I get full pack voltage but when I give it full throttle I the voltage varies from about 16 to 18 volts. Reversing the procedure give me the same results only with a minus.Minus full pack voltage and minus 16 to 18 volts at full throttle.

[JohnnieB]

Full pack voltage between B- and M- with pedal up, but only drops to 16V to 18V with pedal down.

If the pack voltage is still 44.4V, 16V out means the PWM duty cycle is about 64% and at 18V it is about 59%.

What is located between B- and M- is the MOSFETs and they are turned on and off about 18,000 times a second. How long they stay on each time they are cycled on and off is the duty cycle.

When they are not turn on at all, or only very briefly during each cycle (0% duty cycle), the entire applied voltage is dropped across them.
When they are turn on all the time or very near all the time during each cycle (100% duty cycle), the none of the applied voltage is dropped across them. (More correctly, they drop about 0.1V per 100A of current flow through them, so when maxed out a DCX400 will drop about 0.4V between B- and M- when everything is working properly.)

The duty cycle of your controller's output to the armature appears to be going up to about 60%, so I suspect there is a throttle issue. Either the throttle signal input to the controller is only telling it to go to 60%, or the controller's ITS circuitry is only interpreting a 100% throttle signal as a request for 60% output.

What I'd do at this point is connect a laptop to the controller and make sure the Maximum Output Current and Top Speed sliders are set to.

Then I save a data log while driving cart at top speed and then review it to see what the highest % Throttle was reached.

--------
Or I'd open the pedal box under the floor mat and measure the voltage drop between Pin-1 on the DCX controller and the white wire on the ITS Sensor and between Pin-2 on the DCX controller and the black wire on the ITS Sensor.

If you get more than 0.1V on either, something is wrong with the wiring between the pedal box and the controller.

[scottyb]

Sorry if I missed it - did we get a full throttle signal test up and down? Assuming alltrax DCX is the LED light going orange at full pedal?