alltrax need reprogram when going 48v? help?

[swampland]

ok. lifted a2 wire and tested full battery pack voltage on all cables going to motor as i pressed the throttle
from battery - to cables at motor s1,s2,a2 full bpv, a1 was 1 volt below.
placed all wires back and lifted cable from a1 motor at m- with throttle depressed just a lil -1v fbpv.

cable still lifted m- to a1 cable 23v and throttle depressed 22v
m- to b- 24v 28v

[swampland]

so controller is a variable speed controller (voltage) . if i have full battery pack voltage a1 cable to negative the high amperage circuit should be good, right? is the controller not letting voltage flow from b- to m- ? trying to figure this thing out...

[JohnnieB]

Reconnect all the cables and leave them connected.

Connect DVM's negative test lead to battery pack 's main negative terminal.

Measure and record voltage at solenoid's battery side large terminal.
Push pedal until solenoid clicks and measure voltage on solenoid's controller side large terminal.

Unless those two voltages are identical, all other measurements are more or less meaningless.

It may help to remove the resistor that is connected between the two large terminal on the solenoid while troubleshooting.

[swampland]

sorry johnnie full bpv on battery side and when i depress pedal fbpv on controller side of solenoid

[JohnnieB]

Originally Posted by swampland

1. so controller is a variable speed controller (voltage) .
2. if i have full battery pack voltage a1 cable to negative the high amperage circuit should be good, right?
3. is the controller not letting voltage flow from b- to m- ?
4. trying to figure this thing out...

1. It actually controls the number of amps the motor is allowed to draw.
The output to the motor is PWM (Pulse Width Modulated) DC.
Located between the B- and M- terminals is a dozen or so MSOFETs (Metal Oxide Field Effect Transistor) that are switched on and off at about 18kHz.
When they are shut off all the time (0% duty cycle) the full applied voltage is measured across them.
As the duty cycle increases towards 100%, the average voltage measured decreases because voltmeters average pulsed DC.
When the MOSFETs are turn on, there is about 0.5 volts per 100A of current flow through them, so the voltage between B- and M- will not completely reach zero if current is flowing.

2. If the A1 cable is the one connected to M-, having full battery pack voltage there is a good indicator that the high current circuit is intact, but it doesn't necessarily mean that it is good. A DVM has a high impedance input and will read good voltage on cables and connections that won't pass high current. (But they usually get hot and smoke or spark if they are bad)

3. In an earlier post, you stated the voltage went from 28V down to zero when the pedal was pushed. That indicates the MOSFETs are being turned on. That in turn means the controller is trying to do its job. It may have some issues, but if any exist, they are being masked by the controller not getting the voltage it should be getting from the external circuit.

4. The fog eventually clears. The attached may help. It is a series wound motor drive reduced to its simplest form and showing only the high current circuit. There is a single current path from one side of the battery to the other.

[JohnnieB]

Originally Posted by swampland

sorry johnnie full bpv on battery side and when i depress pedal fbpv on controller side of solenoid

That means the solenoid is doing its job.

What controller do you have AXE or SPM. I need to be looking at correct schematic to troubleshoot further.

[swampland]

its an AXE

[JohnnieB]

1. Disconnect the Pre-Charge resistor that is connected between the solenoid's two large terminals. (Reinstall after cart is running)

2. Jack rear tires off ground and place on Jackstands.

3. Install jumper wire from battery pack's main positive terminal to solenoid's small terminal with red wire attached.

4. Place F/R lever in F position.

5. Verify LED on AXE controller is on steady Green.

6. Attach your DVM's negative test lead to battery pack's main negative terminal and leave it there unless otherwise stipulated.

7. Using DVM's positive test lead, measure voltage at Controller's B- terminal. It should be Zero volts.
If not the B- cable to battery pack is bad.

8. Measure the voltage at both ends of every other high current cable (Should be 12 more cables - 12 total)
All 24 of the test points should read full battery pack voltage.
If not, the problem is between the two point where the voltage becomes less than Full battery pack voltage.