ITS problem?

[yurtle]

I don't recall the reading on my ITS, but it wasn't open. What range did you have your ohmmeter set on?

[BobBoyce]

Originally Posted by billbeach

When I checked the continuity through the ITS it is open. Is this normal?

You should read some impedance there, it is a coil and other components.

[billbeach]

Originally Posted by yurtle

I don't recall the reading on my ITS, but it wasn't open. What range did you have your ohmmeter set on?

My meter was set to ohms. Not kilo or micro. Also, my meter will automatically adjust when measuring volts & resistance if needed for polarity or value.

[billbeach]

Originally Posted by BobBoyce

You should read some impedance there, it is a coil and other components.

My thoughts also. I should read (measure) something other than infinity.

[yurtle]

Are you measuring the actual ITS, or the wires in the MOLEX plug?

[billbeach]

Originally Posted by yurtle

Are you measuring the actual ITS, or the wires in the MOLEX plug?

I am measuring the actual ITS. The black & white wires are disconnected.

[yurtle]

Sounds like your ITS is bad. Is the case cracked?

They aren't cheap. Do you have a friend with an ITS buggy, to try his in yours? If not, look on the "for sale" forum on this site. You might get lucky.

[billbeach]

Originally Posted by yurtle

Sounds like your ITS is bad. Is the case cracked?

They aren't cheap. Do you have a friend with an ITS buggy, to try his in yours? If not, look on the "for sale" forum on this site. You might get lucky.

I'll inspect the ITS when I take it out. Unfortunately, I don't have a friend whose ITS I can borrow for a test. Since it looks like everyone is reading some resistance other than open, I guess I'll have to bite the bullet. You are right, they are not cheap. It'll be the end of the week before I can take it out and check it. Thanks for your help.

[JohnnieB]

The ITS sensor is a proximity detector whose current (amperage) throughput varies with the relative proximity of the iron slug moved by the throttle pedal.

Attached is a schematic of what is inside the sensor.

Also attached is how to test the ITS circuit, two thirds of which is inside the PDS controller.

The ITS voltages are measured with the Negative Test lead attached to the main negative terminal of the battery pack.

FWIW: Measuring the voltage between the black and white wires is how to check the ITS circuit when an Alltrax Controller is installed - The same ITS sensor is used, but Alltrax powers it differently, probably to avoid Patent infringements. (The ITS patent document is also attached - it contains a theory of operation for the device.)

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The original voltages posted were within specs for a PDS controller. The voltage on Pin-4 is low when pedal is down, but the 15V +/-1V spec is with pedal up.

Also a bad ITS sensor isn't consistent with the symptoms stated in the first post of this thread.

Going a few feet and stopping is typically a solenoid not activating or a solenoid with bad contacts. Traveling further when pedal is only partially pressed is a further indication of a solenoid issue.

Basically, the charge placed on the filter capacitors via the pre-charge resistor has enough energy to move the cart a few feet, and if the charge had been replenished by the battery pack being directly connected via the solenoid contacts, the cart probably would have kept moving.

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Personally, I'd reconnect everything and measure the ITS voltages again as show in the troubleshooting tree with negative test lead attached to B- at battery pack.

[billbeach]

Originally Posted by JohnnieB

The ITS sensor is a proximity detector whose current (amperage) throughput varies with the relative proximity of the iron slug moved by the throttle pedal.

Attached is a schematic of what is inside the sensor.

Also attached is how to test the ITS circuit, two thirds of which is inside the PDS controller.

The ITS voltages are measured with the Negative Test lead attached to the main negative terminal of the battery pack.

FWIW: Measuring the voltage between the black and white wires is how to check the ITS circuit when an Alltrax Controller is installed - The same ITS sensor is used, but Alltrax powers it differently, probably to avoid Patent infringements. (The ITS patent document is also attached - it contains a theory of operation for the device.)

--------
The original voltages posted were within specs for a PDS controller. The voltage on Pin-4 is low when pedal is down, but the 15V +/-1V spec is with pedal up.

Also a bad ITS sensor isn't consistent with the symptoms stated in the first post of this thread.

Going a few feet and stopping is typically a solenoid not activating or a solenoid with bad contacts. Traveling further when pedal is only partially pressed is a further indication of a solenoid issue.

Basically, the charge placed on the filter capacitors via the pre-charge resistor has enough energy to move the cart a few feet, and if the charge had been replenished by the battery pack being directly connected via the solenoid contacts, the cart probably would have kept moving.

-----------
Personally, I'd reconnect everything and measure the ITS voltages again as show in the troubleshooting tree with negative test lead attached to B- at battery pack.

Thank you very much. I will do exactly what you recommended. It will be the end of next week before I can try. Thanks again.