Lamp Re-Wiring

I took Friday off with the hope of having a four day weekend of flying some hours off but I decided I wanted to get a handle on my lamps first. Having done some more reading I had discovered that the battery fault lamps needs 12V, and the rectifier lamp also needs 12V – both were wired to ground.

After some tracing of wires, looking around, I decided to splice into the pilot grip switch as it is connected to the master switch and the wire is right there by the pilot door. After making sure I was going to cut the right wire I cut it, stripped it and added a new wire that would go to the lamps.

At this point I made what could have been a costly mistake – I was testing the pilot grip still worked but had left the new wire stripped bare at the other end and it touched one of the side panels. Instant 12V to ground and the grip no longer worked. I did not notice any sparks.

I spent some wondering just how many things I’d have to replace – did I short just the grip, or the flap and trim motors as well? Either way, this was not good.

So I carried on hooking the wire into the 12V on the lamps (which meant moving the fault wires as well as they were connected to the 12V input – yeah, I really didn’t read up on how to install the lamps) and for reasons I don’t know why I tried the pilot grip again and now it worked. The surge protection on the power panel must have saved the circuit and then reset after a while. Well worth the money right there!

I can’t test the battery light without letting it run down but I did try the rectifier and there was nothing. A little more reading says that when the engine isn’t running the terminal is grounded and so the light comes on, but when it is running it has 12V and so the light goes off. Well, the light was off so Allen suggested I remove the wire and ground it and see what happens – the light came on. So the circuit works but the terminal is not grounded as it should be.

And that was where it was left on Friday, with some homework to do more reading on the rectifier.