Thought I would share a solution to a problem we had.
Our hydraulic jacks always said that the parking brake was not on, so we were unable to use the jacks. I had searched and found others with the problem. One solution was to climb underneath the steering wheel area and wiggle possibly a purple wire. I did that once and just by chance got the light to go off. Never had any luck again, and its extremely difficult to get under there.
Well we ended up spotting the culprit wire from up above while we had the dashboard lifted. It was a blue wire and was just barely clipped on. We used a long pair of pliers and pushed it back on all the way. Problem solved!!
I posted a close up pic of the wire and one a further back to give a perspective of where it is. It's circled in red.