Fanfare came with one of these Bendix units and I nursed it along for years before replacing it. If it is just the lightbulb fix it. That's cheap. But don't spend a lot of money on it. I finally replaced mine with one from Robertson/Simrad which is all solid state and gives you a rudder angle indicator and fluxgate compass included in the unit for free. The old Benmar used to lose fix and make sudden 90* turns. No more. With the new one, unless we are in a restricted waterway, the autopilot is usually on and working. We even use it in rough ocean seas. True, I can steer a little better, maybe 5%, because I anticipate better, but it's a lot more work and concentration holding that compass course. It is even more useful if it is foggy when we have to go slowly because I can concentrate on the water immediately ahead instead of splitting my attention to the compass.
After our trip up the entire eastern seaboard to Nova Scotia (VERY foggy) I added the hand-held controller to the autopilot. Too many stomach crunches leaning forward to hit the dodge button for the millions of crab traps on the way. The hand-held has the same controls and LCD display as the fixed-mount. I had already installed the fixed-mounts at the upper and lower steering stations. It would save money to just get the hand-held and put in a plug for it at each place. Because it can be dropped it is probably a bit less durable than the installed version, but mine has hit the deck a few times without harm. Ours has gotten plenty wet with no problems.
Lately I have read ads for remote control devices supposed to let you run the boat from anywhere on board. Given some of the strange results I sometimes get with my TV remote I haven't pursued any of these.
