[A/S] Weak Brakes

[Fritzs@xxxxxxx]

Help,
my 94 30' Excella does not brake very well. I have the Prodigy controller,  
but I cannot get the brakes to lock up, even on soft ground.
The little hand controller will generate 12V, but the foot pedal usually  
only shows about 4V.
neither method generates much braking power. 
I suspect the ground. I found the panel in front of the couch, and I can  see 
a thick copper wire connected where it should be, but: Where is the other  
end connected?
Can I get too it to clean up the contact?
Fritz