763G aux. hydraulic issues

[shadwarr1]

So, I'll gotten my controller programmed, but my aux. hydraulics still aren't working correctly. The right trigger will turn them on and off, but the right thumb switch does NOTHING whether it's in varible or max flow mode. I pulled the connector off the the right steering lever and checked the ohms from the wires. There are 3 wires for the PWM switch: white, white/black, and white/red. When I probe white and white/red I get 1.1 ohms pushing the switch to the left, and 3.9 ohms pushing it to the right, with 2.6 ohms in the neutral position. When I probe white/black and white/red, the readings are reversed except the neutral position. When I probe white and white/black, it's a steady 4.8 ohms with no change moving the switch. I have checked all 3 of these wires back to the controller connector. Plus I cleaned the terminals and still nothing. I'm at a loss of what to do. I've read about a seperate PWM controller, but I'm thinking that this is just part of the main controller for my machine because I cannot find any other controller. I starting to think now the tech missed something when programming my controller or the ohms are not within spec. I can't find any info on testing the switch in the service manual either. Any help is appreciated! Zak

 

[Tazza]

When you move the thumb switch are the magnets on the control block working? remove the nuts holding the coils, operate the hydraulics and try and lift the coils up, is there any resistance? Hopefully your stems are just stuck.
The thumb switch is a resistor, not a simple on/off switch like the left handle.

 

[shadwarr1]

When you move the thumb switch are the magnets on the control block working? remove the nuts holding the coils, operate the hydraulics and try and lift the coils up, is there any resistance? Hopefully your stems are just stuck.
The thumb switch is a resistor, not a simple on/off switch like the left handle.

Neither one is moving when I move the the thumb switch. The rear coil is the only one that works when I pulled the right trigger switch. The front coil is brand new, and I've checked it by swapping the the coils around. The connector for the rear coil shows 10 volts when I pull the right trigger. But when I move the thumb switch left or right the front coil connector AND/OR the rear coil connector show no voltage. When I connect the rear connector to the front coil and pull the right trigger it opens the front valve no problem, this seems to be an issue with either the the thumb switch or the controller itself. I have tried to look at the wiring schematic to see which wires lead from the controller to the front coil connector but the picture is really blurry. The wiring seems fine around the front coil connector, and I even stripped some of the wire insulation off to probe from there in case the connector was bad. You would think though that if the thumb switch is working that at least the hydraulics would work in one direction since the rear coil works with the right trigger pulled. I'm about to take this thing back to the dealer, it's driving me crazy!!!

 

[Fishfiles]

Neither one is moving when I move the the thumb switch. The rear coil is the only one that works when I pulled the right trigger switch. The front coil is brand new, and I've checked it by swapping the the coils around. The connector for the rear coil shows 10 volts when I pull the right trigger. But when I move the thumb switch left or right the front coil connector AND/OR the rear coil connector show no voltage. When I connect the rear connector to the front coil and pull the right trigger it opens the front valve no problem, this seems to be an issue with either the the thumb switch or the controller itself. I have tried to look at the wiring schematic to see which wires lead from the controller to the front coil connector but the picture is really blurry. The wiring seems fine around the front coil connector, and I even stripped some of the wire insulation off to probe from there in case the connector was bad. You would think though that if the thumb switch is working that at least the hydraulics would work in one direction since the rear coil works with the right trigger pulled. I'm about to take this thing back to the dealer, it's driving me crazy!!!

I am kinda reading in between the lines , what attachment are you trying to operate , you mention pulling the trigger , the trigger is a lock , say with a grapple or 4 in 1 when you use the thumb left or right without the trigger it should open and close , if you hit the lock trigger and go open or close with the thumb it will stay in the position you moved the thumb to before hitting the trigger , in other words if you open the grapple and hit the lock it will stay open and you can still use the thumb to close it but as soon as you let go of the thumb it will open again ------probally a bad controll switch , not that hard to change , you do have to take the wires out of the plug by using a paper clip to release the tang which holds them in and best to make a color chart of where each wire goes before taking it apart , the plug has letters on it for each slot like black /white stripe =a , etc , what I do is cut the plug off with an ich or so of wire sticking out , after putting the new one in thru the tube take one old wire at a time out and put the correct new wire in ----don't know how your dealer is about taking back electrical parts , you can plug a new switch in without going thru the tube to see if that fixes the problem -----

 

[skidsteer.ca]

I am kinda reading in between the lines , what attachment are you trying to operate , you mention pulling the trigger , the trigger is a lock , say with a grapple or 4 in 1 when you use the thumb left or right without the trigger it should open and close , if you hit the lock trigger and go open or close with the thumb it will stay in the position you moved the thumb to before hitting the trigger , in other words if you open the grapple and hit the lock it will stay open and you can still use the thumb to close it but as soon as you let go of the thumb it will open again ------probally a bad controll switch , not that hard to change , you do have to take the wires out of the plug by using a paper clip to release the tang which holds them in and best to make a color chart of where each wire goes before taking it apart , the plug has letters on it for each slot like black /white stripe =a , etc , what I do is cut the plug off with an ich or so of wire sticking out , after putting the new one in thru the tube take one old wire at a time out and put the correct new wire in ----don't know how your dealer is about taking back electrical parts , you can plug a new switch in without going thru the tube to see if that fixes the problem -----

Yes the trigger is to keep pumping oil. like for a hoe or brusher, pull it once and flow locks on, pull again to shut flow off.
Trigger only flows 1 way, not for controling cylinders, However you can swap the plugs at the coils to test the hydraulic components and coils on the reverse flow side of the valve as a test if you want.
It sounds to me like you have a defective thumb switch and may have to change that switch group on top of the handle. When the thumb lever is fully over left or right it should have the same resistance as the trigger switch when itis pulled.
Thumb right or trigger closes the exact same circuit, the only difference is the thumb is a momentary switch (does not lock on) and the trigger stays on until you pull it again.
Ken

 

[shadwarr1]

Yes the trigger is to keep pumping oil. like for a hoe or brusher, pull it once and flow locks on, pull again to shut flow off.
Trigger only flows 1 way, not for controling cylinders, However you can swap the plugs at the coils to test the hydraulic components and coils on the reverse flow side of the valve as a test if you want.
It sounds to me like you have a defective thumb switch and may have to change that switch group on top of the handle. When the thumb lever is fully over left or right it should have the same resistance as the trigger switch when itis pulled.
Thumb right or trigger closes the exact same circuit, the only difference is the thumb is a momentary switch (does not lock on) and the trigger stays on until you pull it again.
Ken

I'm trying to operate a breaker attachment. It will only work in one flow direction. When I pull the right trigger the machine bogs down, hose's get stiff, but the breaker does nothing. When I swap the electrical connectors around on the coils the breaker works great! I'm gonna try and jump the terminals with a wire for the thumb switch circuit and see if that does anything. If it works, then I will know for sure the thumb switch is bad. I just didn't want to fry something if I do that. I seems odd that with that low of a resistance it would do something, but who knows. Maybe the controller is that sensitive. Funny thing is I have no codes. Zak

 

[Tazza]

I'm trying to operate a breaker attachment. It will only work in one flow direction. When I pull the right trigger the machine bogs down, hose's get stiff, but the breaker does nothing. When I swap the electrical connectors around on the coils the breaker works great! I'm gonna try and jump the terminals with a wire for the thumb switch circuit and see if that does anything. If it works, then I will know for sure the thumb switch is bad. I just didn't want to fry something if I do that. I seems odd that with that low of a resistance it would do something, but who knows. Maybe the controller is that sensitive. Funny thing is I have no codes. Zak

The switch is not a typical on/off switch its a potentiometer. The resistance changes depending on how far you move the switch. This is how it knows how much oil to move for vairable flow operation.
Hopefully its just the switch in the handle, nice and easy to change out.

 

[shadwarr1]

The switch is not a typical on/off switch its a potentiometer. The resistance changes depending on how far you move the switch. This is how it knows how much oil to move for vairable flow operation.
Hopefully its just the switch in the handle, nice and easy to change out.

Seriouly, just the switch can be changed and not the rest of the switches as one assembly? Cause that would be sweet!

 

[shadwarr1]

Seriouly, just the switch can be changed and not the rest of the switches as one assembly? Cause that would be sweet!

Nevermind, the whole top assembly has to be changed. Bobcat wants over $200! Yikes! I might have to just make do with swapping the connectors around for now. Luckily this is for personal use for now, but if I decide to do some side work in the future I'll have to fork over the cash. Thanks everyone for your help! I hope it's just the switch.