Netters, Lesson one: I've been trouble shooting a problem I was having switching out my standard position lights with new LED lamps to cut my electrical load by 4 amps or more. I installed the tail light and great, it worked. I replaced the left wing light and nothing. I put the standard bulb back in and it lit up. Back to the LED bulb. No deal. I went to the other wing and same thing. I tried the bulbs in the tail and they both lit up. Now what. I cleaned the sockets. Still no go. That was yesterday evening. I closed things up in case I wanted to fly today and went home. Driving home I remembered I had two good used sockets in my parts bin in my garage. I took them to the airport with me today and tried again. Still no luck. I put things back together to possibly fly today. Meanwhile a friend called and wanted to go flying. (answer to follow)
He showed up in his RV7A and we flew out for lunch in his RV. Lesson two: On the way back I asked him to let me fly and make a low pass on a friends grass strip. What great fun!!! On climb out he said to take us back home (letting me fly). As we approached the airport he asked if I wanted to land the RV as they had just installed toe brakes on the right side. Who could turn down that offer? A nice straight in approach, smooth touch down, and he congratulated me on a nice landing as we rolled out. At about 20 mph I approached a runway exit and gave a bit of rudder to head that direction. As I began to apply a bit of brake for the turn strange things started to happen (castering nose wheel, brakes to steer). For several seconds I felt totally out of control. My friend starts yelling, HEY, what the H#@@@ !!! We were headed for the grass so I locked them up. I could hear the tires chirping but no other options at that moment. We stopped 15 feet short of the grass and I asked him to get us off the runway as something on my side just wasn't responding the way it should. On the taxiway we checked the brakes on my side and sure enough, they had been plumbed BACKWARDS, left peddle right brake, right peddle left brake. I had helped to install the fluid after the install and we checked the brakes in the hangar and they locked up just fine but I was the first person to fly right seat and use them in motion. Lesson learned: do a COMPLETE checkout on any system that has anything to do with aircraft control before you do something stupid. Back to my light problem. After he left I decided to take one more stab at the problem. This time I got out my meter to see where I was loosing connection. I placed my red lead on the center power pin and the black lead on the socket side. -12 volts !!! I knew instantly what the problem was. These are LED lamps with the operative word being (D)iode. The power polarity has to be correct as they only conduct one way. The polarity made no difference on the incandescent bulbs so they worked just fine. Lesson learned: Double check the polarity on any type of LED light, no matter where they are installed. With them working and the artificial horizon I recently installed, the only obstacle between me and some night flying is getting my second strobe operating again. More fun to follow.................. Wishing a SAFE AND JOYOUS NEW YEAR to all. YEEEEEE HAAAAAAAAA Larry Flesner
