753 Aux Hydraulics lights and button not working

So I have a 1991?? 753 with BOSS control, that I have had for 15+yrs. The Aux Hydraulics are not working like they should. The Aux Hydraulic Button and lights do not work and change form key start to key start. Sometimes I have no lights, sometimes one, and sometimes two, but one thing is always the same, and that is that the button on the Aux Hydraulic control does not make a change.
It used to activate the Aux, and one light would work, push a 2nd time, and it would lock on. I use it with the backhoe attachment and brush shredder I use.
no mater what the light, I can open and close my grapple but switching seems off based on the sound of the flow. It works but not like it should.
I have checked the control buttons on levers and they are good. The actuate the control solenoids on the valve body.
I think the Aux Control Module PN 6671669 Was 6669529 may be bad.
One corner seems to be bulging out like the potting material has pulled free and let water in???
Does my issue sound like a bad Aux Control Module or should I look at something else?
Is there anyone that I can send it to to test before I buy a new one for $600 or used for $300.
I would even consider buying one, that I could return for a restock fee if not to bad.
Any testing or suggestions are welcome.

Thanks

When my aux hydr controls stopped working, I was convinced I needed the module….but I found one handle harness was connected to the wrong mate under seat, and chewed wires at the module. So my advice is to very carefully inspect all wires first, upper left panel, upper right panel, under seat both handles and control module harnesses, solenoids for aux hydr activation. I spent hours looking at the wiring diagram in the service manual. That's how I found the mismatched handle connector. Bobcat service tech connected it to wrong mate.

Look on eBay for isocell. They may test for a fee. They rebuild many bobcat modules.

I do have the service manual, and I ohm'ed out every wire and check all grounds and even the in-line diodes. All checked good. It worked a while back and nothing has been unplugged. I also looked for rubbing or worn wires. No bare spots found. It is the lights and the switch not working, when it did before that has me thinking the module.. thanks for the suggestions.. iwill look at the Ebay site you suggestions.

Markle said:

Look on eBay for isocell. They may test for a fee. They rebuild many bobcat modules.

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Can you double check the name isocell? Can't seem to find it on eBay.

Here is the website: