Author Topic: Nav lights not working? (Read 1478 times)

Daniel Vieth · « **on:** July 12, 2010, 02:37:32 PM »

I have a 1963 p-35 and the nav lights work for about a minute and then pop and the switch is off. i think the breaker/switch is probably bad but thought i would check around before investigating more myself. if i turn it back on after it pops it will work for about 30 sec and the turn off again. then it just turns off right away and i have no nav lights. any insight would be of great help

Thanks

Tracy Ryan · « **Reply #1 on:** July 12, 2010, 02:56:45 PM »

Have a person at each nav light. Turn the nav light switch on to determine if they all come on, but don't wait for the switch to trip. That could be overheating the wiring and causing unseen damage. Most likely you'll have one that doesn't, or is extremely dim.

I would then remove the nav light wire(s) from the load side of the switch. Engage the switch and see if the switch trips. If it does, then the switch should be the culprit. If it doesn't, then it's a matter of finding the shorted wire. If your lucky, you still have three wires that were attached to the switch. They should be labeled L17A18 (Tail), L18A18 (Right) and L19A18 (Left). Remove the nav light bulbs and check each wire for a short to ground.

Tracy Ryan2010-07-12 23:02:32

Chuck Waldrop · « **Reply #2 on:** July 12, 2010, 09:48:28 PM »

Nicely Done Tracy

Chuck

Daniel Vieth · « **Reply #3 on:** July 12, 2010, 11:20:16 PM »

Thanks.... I'll check these things this weekend and leave my nav lights alone until then.

Tom Pelz · « **Reply #4 on:** July 13, 2010, 12:12:45 PM »

Dan,

I have had the problem also. I found that some corrosion had gotten into the bulb sockets, I had to replace one socket (which is available from Aircraft Spruce. Unfortunately not cheap - about $100 in parts.

Tom

Mel Craig · « **Reply #5 on:** July 16, 2010, 08:18:45 AM »

I had this same problem on my P35. I checked the load for each bulb and it was 1.8 amps. This load times 3 exceeds the 5 amp switch. I disconnected one light and the breaker never popped. Did this with each light (i.e. any 2 on and 1 off). The breaker never popped. Ordered Whelens strobe lights (1/4 amp each), installed same and no further problems. Be sure that the polarity is correct too, as mine was reversed. The way you know is that the LEDs are polarity sensitive and at first the LEDs didn't work. Talked to Whelen and they advisded to check the polarity... what do you know? It was wrong. Fixed the wires and all is fine. Spruce has some that are very inexpensive, about $100 for all 3. If you do Whelens, it is $375. Hope this works for you.

Daniel Vieth · « **Reply #6 on:** July 16, 2010, 09:12:33 AM »

So i checked the NAV lights with the plane not running and they dont break. thinking it may have somthing to do with the generator giving them just that little extra kick that is making them pop. I will measure the amps at each bulb this weekend and I also ordered a new breaker. if i need to ill look into the swapping out the lights with more eficiant ones. thanks for the help and i'll post what i find. thanks again. oh and all the lights are as bright as bright can be. didnt find a dim one while inspecting.

Tracy Ryan · « **Reply #7 on:** July 17, 2010, 10:47:22 AM »

Mel, that would be correct for 26 watt bulbs, but 21 watt bulbs (Grimes 1512) is what is supposed to be installed. With 3 x 21 watt bulbs, that would be 4.5 amps. That's still not a lot of margin for the breaker given some contaminants in the connections and aging wires, but we've never had a nav light breaker trip and I've never felt the breaker getting even warm.

Daniel Vieth · « **Reply #8 on:** July 18, 2010, 06:49:46 AM »

So i got my new led nav lights and problem solved. thanks for all the help

dan

Mel Craig · « **Reply #9 on:** July 18, 2010, 07:49:30 AM »

Tracy,

I checked Whelen catalog and their web site and the only bulb available for nav lights is the 1290. The 1215 is gone and, as you said, the 1290 is a 26 watt lamp. Isn't getting educated a lot of fun? I sure hope I don't run out of money before I get smart. Thanks for the reply.

Mel Craig · « **Reply #10 on:** July 18, 2010, 07:53:01 AM »

Tracy,

I have egg all over my face; I found the 1512 bulb in their catalog. I apologize. Mel

John Calvert · « **Reply #11 on:** July 27, 2010, 05:06:35 PM »

Daniel:

I had a nav light problem and thought it was the C/B switch. With new switch the problem was still there. I did some searching and found the wire in the wing in two places where they crossed the ribs had worn thru the insulation. After making a repair to the wires no more problems.

Tom Pelz · « **Reply #12 on:** August 07, 2010, 06:58:56 AM »

Gentlemen:

Check out aveo engineering. AveoEngineering.com.

They have some really nice LED which can replace the entire position light. It also includes strobes etc.

I saw them today at Paradise Interiors, in Reedsburg, WI. He was getting ready to install them on a C172. They are STC'd. He said the cost is about $500 or less.

The nice thing is when they are all ON, they only draw about 6 AMPs total.

Tom