Hello all,
So, this is for those that know 90s era diesel platforms. I have a '93 Mitsubishi FUSO cab-over. It's a neat little truck, and I love driving it. It has almost 300,000 miles on it and still runs smooth and fires right up. However, the exhaust brake doesn't work, and I am running out of ideas and what I can do myself to find the issue. How it works is that it has an on/off switch operated by the wiper blade lever on the steering column. So either the engine brake indicator lamp is supposed to illuminate on the dash when the switch is flipped on, or the lamp turns on when the engine brake is actuated, but it does neither. I can turn the engine brake on via the switch, but it never actually functions. I've tried utilizing it at various speeds and RPMs but I feel, hear, or see nothing. I've opened her up and from what I can see and feel, everything is connected and intact, however I can't get beyond a certain point inside the guts of the steering column. And of course, the fuse is stilll intact as well. Google searching for this particular truck has been hard, since there aren't many forums for this platform at all. Or at least the discussions I have found are for the Canter models and the 4x4 newer FUSOs. If anyone if familiar with this particular platform, I'd greatly appreciate hearing from you. 
Thanks guys!