Weak eyes, no, weak head-lights
My 2000 Monaco Knight coach has always been short in the head-light area. I did not drive much at night, so was not too concerned until I made an all nighter through the Siskiyou Mts a couple years ago. After doing some measurements, I determined that the issue was just a voltage issue. Even though there is 13.8 Volts at the battery, there was far fewer of them precious volts left at the bulbs. There is a lot of wire and connectors and switches used in the coach to get from the battery to the bulb. The wires, connectors and switches all have a voltage loss when caring a heavy power load. I was lucky to get 9 volts at the bulb. The Ground wire is just as important as the hot wires, so always include it in the mix. The coach makers like to plug and play with the wiring harnesses. To fix the problem, I added a couple ice cube relays upfront near the head-lights. The relays coils (85 & 86) were connected to the wires that had provided power to the head-lights. Some relays have a diode inside the unit, so polarity is important when connecting these wires. The relays draw only a fraction of the current that the lights do. Then I grabbed two heavy duty fuse wires (15 Amp), (at least a 14 gauge wire. 12 gauge is even better) to make two new power lines for the lights. The fuse end of the wire needs to be close to the power source. Do not connect the power up until the other connections are all done. I used two fused wires, as one does not want all of the lights connected to one fuse. Kinda an all of the eggs in one basket thing. The fuse wires are connected to the relay contacts (30) on the relays. The other relay connection (87) is then connected to one wire of the light bulb. Now a good short ground wire is needed to be added from the other side of the bulb to a good solid ground close to the head-light. Now is the time to connect up the new fuse wires to the power post. I now have ample power to the lights. I changed my low beam from the head light switch to follow the IGN, so I always have low beams on while driving. If you do make a change like this, be sure to document the changes in the owners manual as well in the fuse chart.