Changing joystick function

[BeezFun]

I have a Gehl telehandler, the joystick uses left/right for telescope function, and the thumb flipper labeled R1 for curl/dump. I'd like to change it so it works like a more conventional joystick, which has the the curl/dump function associated with left/right for the joystick and the telescoping function associated with R1. Here's the joystick:


I've stared at the electrical schematic, and I think if I just exchange the pair of wires for the left/right stick motion with the wires for R1 that should work. Both are potentiometer based and the specs show both sending the same voltage range signal to the ECU. The ECU uses that input voltage to decide what analog voltage to send to the appropriate electro valve. Ironically the schematic has two places that show the left/right stick motion being associated with the curl/dump function. I think that's because Gehl was bought by Manitou and that's how Manitou does it. So their drawings didn't get merged properly.
Anyway, does anyone see any reason this change won't work? I don't want to destroy anything...

 

[oldnslo]

Either change wires there of if valve stack is accessible change wires at the valve IF individual connectors for each valve section.

 

[BeezFun]

Either change wires there of if valve stack is accessible change wires at the valve IF individual connectors for each valve section.

The valve stack is accessible, but it uses different valves for the two functions so I don't think it would work to switch them. Also, there are ECU logic controls on the telescope that wouldn't apply properly to the curl/dump cycle. So I think my only option is to make a change in front of the ECU. My concern is that there is something different about the voltage signal coming from R1 and the joystick. I'm guessing I'll have a lot more control over the curl function because the joystick has so much more travel but uses the same voltage range as R1. Which is another benefit from my perspective.

 

[oldnslo]

output to valves could be milliamp vs voltage but either way suspect you are correct in changing wires at input vs out put. Doing that should have minimal effect on control logic.

 

[BeezFun]

output to valves could be milliamp vs voltage but either way suspect you are correct in changing wires at input vs out put. Doing that should have minimal effect on control logic.

Thanks, I have to work up the courage to make the switch. It takes about an hour to get the console all apart to get to the connectors. Then it will probably be 5 minutes to make the change.

 

[Tinhack]

According to my watch, you should be close to having than done by now.

 

[BeezFun]

According to my watch, you should be close to having than done by now.

I'm still at the liquor store picking up some courage.

 

[oldnslo]

I'm still at the liquor store picking up some courage.

Celebrate the victory or drown your sorrows.

 

[BeezFun]

Question on the circuit diagram. The diagram for R1 looks like what I'd expect for a potentiometer roller switch:

But I don't understand the circuit diagram for the joystick. I recognize the potentiometer symbol that has +5v and GND coming in the top and bottom. The output of the pot goes through the triangle that looks like a diode that's missing its vertical line. I'm guessing the rectangle is supposed to be a resistor? Is this typical for a joystick diagram?

 

[oldnslo]

Do you know what brand of Joysticks you have on that Gehl? Reason for asking is that my limited experience and know of joy sticks is that they have lots of options and may not be the same from Danfoss, Rexroth, OEM, etc. might have to try and find the manufacturers data sheet to see if it explains the electrical diagram.

 

[BeezFun]

Do you know what brand of Joysticks you have on that Gehl? Reason for asking is that my limited experience and know of joy sticks is that they have lots of options and may not be the same from Danfoss, Rexroth, OEM, etc. might have to try and find the manufacturers data sheet to see if it explains the electrical diagram.

No, I might find out once I remove the console and get a look at the base.

 

[BeezFun]

OK, change in plan. I went on an electronics forum and got more info on how that R1 switch works. It has a null point in the middle of the 0-12V range, so voltages 0-6v cause the cylinder to move one direction, voltages 7-12v cause it to move the other direction. That voltage is output on pin 6. The pins labeled 4 and 5 are tied together and send a logic signal to the ECU telling it that the switch has been moved and that the ECU should start applying the appropriate output voltage to the right contacts on the electrovalve depending on the direction the switch is moved.

The joystick left/right motion has two signal connections to the ECU. It sends 0-12V on one pin if moved to the right and 0-12v on a different pin if moved to the left.

So there's no (easy) way to interchange the connections between the joystick and the thumb switch. I'm going to look at @oldnslo's suggestion to make the change on the output side of the ECU. So I'll be having more questions about electrovalves and will probably start a different thread.
tnx for all the help