M20M Panel Lights and Dimmers

[Mark Nit]

Hey Folks, I'm a newbie with MooneySpace and also with my 1991 M20M TLS. And because I'm located in a smaller center in Canada, there aren't a lot of Mooney experts near by. So, I would sure appreciate any suggestions you may have.

Very recently, I've noticed that my panel lights, glareshields lights and the yoke-mounted map lights are not working. The only thing I've been able to determine so far is that the panel fuse is good. And because all of the lights are out, I'm assuming that the bulbs, dimmer switches and wiring are probably not the cause the problem. However, after reviewing the maintenance manual and the parts manual, I still have no idea how to trace the problem back to the aft electrical rack.

So, any suggestions on how I can start debugging this problem ??

[jfdez]

I had the same issue on my M20M and to my A&P's surprise, he discovered that the factory had the wrong cicuit breaker installed.

[Skywarrior]

Were the outside Nav lights on at the time? The interior lights are tied to them.

[donkaye, MCFI]

I also have a 1991 Bravo. Many years ago I had the same problem. It was a difficult problem to find in my case. It turned out to be blown output power transistors in the dimmer Box found by my Avionics shop.

[thinwing]

Could be even simpler...the multiplug connector directly behind and into panel/glareshield reostats in my aircraft unlugs very easily....check to make sure its pluged in all the way..its a little hard to get two...we used a little rtv to secure this plug and no probs for last couple years..kpc

[JohnB]

I have a 93 Bravo, and had a very similar issue. My entire lower panel of lights and several backlights on instruments didn't work. First mechanic changed fuses and bulbs without success. Took it to an avionics shop who found that there was a faulty ground wire to this circuit, and the wire was replaced and it works fine now.