Re: 1977 115 evinrude has tilt and trim motor ,3 wires comming out but no control box
OMC makes a dash-mounted trim switch and panel which would work. Most folks like the switch on the control box handle. You may be able to find the correct switch and handle parts on the Bombardier parts diagram web pages. Then see if the local dealer can still get the parts. If not, you should be looking at marine salvage yards. If the engine was a recent purchase, perhaps the original owner still has the trim box. Those salvage yards are good places to find the trim control box you are looking for. You can't run the trim system without the box. The trim switch will burn out prematurely when the "up" position is activated over time due to high current loads.