'06 TXT PDS No Go...

[JigginJim77]

ITS Throttle Testing Results Direction in Forward for all tests.
@ Controller;
DVM Neg @ B-, Pos @ C4 White Wire; Key off, Tow - 0v. Key off, Run- 9.24v. Key on, Tow- 0v. Key on, Run-7.47v
DVM Neg @ B*, Pos @ ITS white wire; Key off, Tow- 0v. Key off, Run - 9.24v. Key on, Run-7.47v (results same as @C4 white wire)

@Pedal Box
DVM Pos@ ITS white wire, Neg @ ITS black wire; Key off, Run- 2.74v Key on, Run- 6.78v (pedal up), 4.01v (pedal down)

Pretty sure I have a short somewhere. I did this testing out of curiosity. Thie following shouldn't be happening, correct?
DVM Neg @ B-, Pos @ frame near pedal box; Key off, Tow - 5.8v Key off, Run - 17.7v Pedal up, 11.1v Pedal down. Measured voltage drops as I touch DVM Pos @ points on frame away from Pedal Box.

[JohnnieB]

Originally Posted by JigginJim77

Okay, early morning testing. Pack voltage at 37.6v

scottyb- Alltrax monitor tab shoes throttle operating from 0 -100% as pedal is depressed. Controller goes from solid green to flashing yellow- Throttle wide open but controller is in Current Limit, a normal display status per the manual.

JohnnieB- B- to M- gives 37.6v at solenoid click, only drops to 17.1v at full pedal. ITS black to white wire shows 6.78v drops to 4.01 at full pedal.

I'll check the connections at the motor. Power cables are new 2ga cables, but F1 and F2 are stock.

A blinking yellow light may be a normal display status, but the reason for it is very likely to be abnormal. For some reason the controller's output is being current limited. Current limiting the output is a feature Alltrax added to their latest generation of controllers to prevent the controller from being destroyed when the was a catastrophic motor failure, or other low impedance event in the output circuit(s).

Could be something resembling a short between the A1 & A2 cables or the F1 & F2 cables. Or it might be the the voltage between the ITS wires being way out of spec.

I'd start with troubleshooting the ITS first.

Locate the 4-pin molex connector at the end of the grey cable from the pedal box and disconnect it from the cart's wiring harness. Check it for corrosion, spray clean and reconnect.


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You posted while I was typing.

I'll be back after looking at your numbers

[JohnnieB]

It appears that you have undesired continuity between the black and white wires someplace.


The EZGO ITS Sensor draws more current when the iron slug connected to the throttle pedal is inserted into it and Alltrax feeds the ITS sensor with a constant current source. I don't know how many amps the ITS Sensor draws when the slug is not inserted, but it takes 10V to push that number of amps (probably milliamps) through it while it only takes 6V to push that same amount of current through it when the slug is fully inserted.

The Alltrax controller interprets 10V between the black and white wires as a request for 0% throttle and 6V as a request for 100% throttle.

Since the voltage you are seeing is 6.78 with pedal up (slug not inserted) the impedance between the black and white wires is rough equal to what it normally is when the slug is about four-fifths inserted.

That means the ITS sensor is bad (has gotten wet or damp) or there is cross-talk between the black and white wires.

[JigginJim77]

On my pedal box harness, the only molex connector is at the C4 controller. I will pull the harness and check the wires inside. I have a new ITS. I get the same voltage readings with the new and the old so it could be the wiring. I was looking at the control harness where it runs under the frame to the FNR and key switch. One green wire has a bare spot where it rubbed through the loom and then the wire. Looks like I'll pull the control harness also

If I put my DVM neg on the B- @ the pack and then touch the DVM pos @ the OEM heat sink, I get voltage even with no key and in Tow- 11v. In Run it is 17.8v. I also get a very small amperage leak, .124 with my DVM set at 20u.

After fiddling with the wire looms my pack voltage went from 37.7v to 37.9v.

You guys don't know me but did I mention I hate chasing electrical gremlins...

[JohnnieB]

Try this.

Put Run/Tow switch in Tow before connecting or disconnecting anything electrical.

Unplug C4 from XCT and measure between pins 3 & 4 (Black and white wires connect to pins 3 & 4)

What voltage do you get when XCT is powered up (steady green LED)?

Plug in C4 and disconnect black and white wires from ITS Sensor in pedal box.
What voltage doe you get between black and whit wires at C4?

I'm not sure what the voltage will be with C4 disconnected, but if it drops much with only the wire between the controller and ITS Senor connected, there is something wrong with the wires.

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The voltages you are reading on the frame are more or less ghosts.

There are no perfect insulators and with a high input impedance voltmeter, such as a DVM, you can read voltages that scarcely exist.

Measure from either pole on any of your batteries to the top of that battery and you will get a voltage reading. Measure from your cart's frame to any pole on any battery and you'll get a voltage reading. However, if you make the same measurements with an old analog voltmeter, you won't measure any voltage due to the far lower input impedance of analog type meters. (Typically about 20kΩ/volt while DVMs are usually 1MegΩ or higher)

[JigginJim77]

With the C4 unplugged the controller flashes 2 green 3 red - High throttle over range. I get 10v @ pins 3&4 of the controller. White and black wires unplugged at ITS and I get 10v. Looks like wires are good.

When I plug white and black in ITS and measure across terminals I get 6.78v pedal up. with old ITS. New ITS measures 6.32v pedal up. Could the replacement ITS be bad also? Is there a way to test just the ITS?

[JohnnieB]

Originally Posted by JigginJim77

With the C4 unplugged the controller flashes 2 green 3 red - High throttle over range. I get 10v @ pins 3&4 of the controller. White and black wires unplugged at ITS and I get 10v. Looks like wires are good.

When I plug white and black in ITS and measure across terminals I get 6.78v pedal up. with old ITS. New ITS measures 6.32v pedal up. Could the replacement ITS be bad also? Is there a way to test just the ITS?

Probably getting the High Throttle over range error because there is no current flow at all, but voltage is going to 10V as it should be for pedal up.

Curious, id you get the high throttle error when the wires were unplugged from the ITS sensor? If so, there may have been some current flow.

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If possible can you rig up some way to connect an ITS sensor between your DVM's test leads and measure the voltage at with the C4 plug unplugged?

That would eliminate the cart's wiring and put an ITS Sensor between pins 3&4. If both the ITS Sensors you have are still reading between 6V and 7V, then I would believe both might be bar.

[JigginJim77]

I do get the High Throttle over range error when the ITS is unplugged. As soon as I plug the ITS back in the error flash stops and controller has solid green ready light.

I did rig up jumper wires for white and black wires right at the C4 connector to plug in to the ITS. Without attaching to ITS, the error code flashes and the voltage reads 10.02v. When I connect the ITS the controller has no error. Voltage across ITS terminal is 6.85v. Pretty much the same as the pedal box harness.

I have a cart shop about a 1/4 mile from me. Maybe they can test both ITS that I have.

[JohnnieB]

Originally Posted by JigginJim77

I do get the High Throttle over range error when the ITS is unplugged. As soon as I plug the ITS back in the error flash stops and controller has solid green ready light.

I did rig up jumper wires for white and black wires right at the C4 connector to plug in to the ITS. Without attaching to ITS, the error code flashes and the voltage reads 10.02v. When I connect the ITS the controller has no error. Voltage across ITS terminal is 6.85v. Pretty much the same as the pedal box harness.

I have a cart shop about a 1/4 mile from me. Maybe they can test both ITS that I have.

Putting them in another cart is about the only way to test them.

I tried to create a standalone bench test for an ITS Sensor a while back, but wasn't able to come up with anything practical.

Attached are a schematic and block diagram for what is inside the black plastic wrapper.

[scottyb]

JB, I'm just thinking out loud but, what about a 12v battery and a steel rod?