03 TXT PDS solenoid/diode trouble?

Fegarex

The gremlins have moved in to my cart I think. I have several issues solved but a new one has come up. I have the standard controller and ScottyB's HD solenoid. After I found out the reed switch was bad things worked fine. I then went back to retighten connections and heard a slight "pop" by the solenoid. Then the cart doesn't move or do I get any solenoid click. The reverse alarm works but just no click. Is there a way to test the diode? I tried a continuity test and it shows nothing. I was thinking either I broke the diode or it was making contact with one of the small connectors.

Any ideas?

BGW

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Fegarex

Still having issues. I found the diode was fine. What I DIDN'T do was install the resistor. I had an Alltrax XCT on before and it didn't require one. I then installed the OE solenoid/resistor and still the same. No click, no move. If I bypass/jump the solenoid the cart will move. I am getting power to the key, power to the FNR switch and have power to the small terminals of the solenoid with the key on. I am assuming the pedal is fine as when I bypass it works.
Everything seems fine except I just don't get a solenoid click or movement. Did I fry the controller? What could I check to know for sure?
The controller is a Curtis 1206MX.
Thanks

JohnnieB

You mighty have just learned an expensive lesson about working on a sepex drive system with the Run/Tow switch in Run. The "pop" you heard might have been the controller saying goodbye.

The Curtis 1206MX and the Alltrax XCT-PDS do the same job, but are slightly different in some ways.

Getting the solenoid to click is a two step process, first you have to get B+ to one of the solenoid's small terminals and then you have to get B- to the other.

With a 1206MX, B+ to the solenoid coil comes in on J1 Pin-4, goes through controller to Run/Tow switch, back through the controller to the F/R switch, back through the controller to the key switch and then back through the controller to the solenoid coil. B- gets to the other side when the pedal switch closes and activates the main coil driver in the controller to connect the B- terminal to J1 Pin-6, which is connected to the solenoid coil by the blue wire.

With the XCT, the voltage follows roughly the same path, except it goes from Run/Tow directly to key switch without passing through the F/R first.

Attached Images

Voltage paths through PDS controller.jpg (138.9 KB, 0 views)

Fegarex

Yes, I think have learned a lot of lessons here!
I am learning a lot about the operation however! After work I am going to look some more with what you told me but I am guessing the Curtis fried because of no resistor. I think it tried to warn me by taking out the reed switch first and then when I bypassed it the fault went to the controller.
Thanks for the info!

scottyb

I'm going to post some information on solenoid bypass here in hopes it helps many people. When a cart will not go people are quick to bypass the solenoid and declare the solenoid no good. This assumption is full of pitfalls.
A solenoid bypass is putting a jumper cable between the 2 big terminals or bolting both cables to the same big post. It is the same as taking both big cables off and bolting them together in the air or running a single cable from the battery pack to the controller B+.
What this is doing is taking the solenoid out of the amperage delivery equation.

What can we determine by doing this if the cart then runs? Well, we know the throttle signal is communicating with the controller and both the controller & motor work.
What can we determine by doing this if the cart then does not run? We know only there is a problem with one of the following; the motor, the controller, or the throttle signal.
We assume you have good battery voltage and when monitored that value is not dropping more than the value of one battery when in use.

It is important to remember what is not learned about the system when a solenoid bypass is used.
Do not assume the solenoid is at fault when the solenoid will not click. There are several switches that must work sequentially before the solenoid clicks (closes). Depending upon your model cart there may be a series like this; reed switch, F&R micro switch, key switch, pedal switch, and an internal controller switch. So bypassing a solenoid takes ALL of these switches out of the analysis. Switches - which are more likely to fail than the solenoid.