Adi Posted March 1, 2021 Report Posted March 1, 2021 Hi folks, I noticed that the left wingtip nav light stopped working in my 1983 J model. I have no idea if it's the bulb or the connection or something more serious, but since bulbs are cheap and 14 CFR part 43 appendix A specifically calls out (17) Replacing bulbs, reflectors, and lenses of position and landing lights. as preventative maintenance, I thought I'd give replacing it a try. How would I go about figuring out what kind of lightbulb I need to replace it with? Quote
Minivation Posted March 1, 2021 Report Posted March 1, 2021 Yes, replacing nav light bulbs are most certainly something the owner pilot can carry out provided that the task doesn't involve any crazy tooling or procedures (it doesn't). Most M20J nav lights use a half-dome type bulb (usually Type 7512-12) that you can easily purchase online (namely Aircraft Spruce). An easy method of identifying the bulb you have is to remove the bulb and look if there's any markings on it that may give you a hint of what it exactly is. As for determining if the bulb failed vs. something else ... one easy way is to look at the bulb's insides to see if the filament is broken. If it is, bulb's dead. If not, then try checking the bulb with a multimeter and if that still checks out OK, then check for aircraft voltage at the bulb receptacle tip compared to the receptacle housing. Statistically, the actual wires in an aircraft rarely fail, so I doubt you'll need to be fishing wires out of the wing. Quote
xavierde Posted March 1, 2021 Report Posted March 1, 2021 @Adi It might also be worth checking the wiring. I thought a nav bulb was dead a few months ago but upon checking, it was just a bad grounding. Quote
warren.huisman Posted March 1, 2021 Report Posted March 1, 2021 Swap left and right bulbs. Does it follow the bulb or the wingtip?Sent from my iPhone using Tapatalk 1 Quote
Adi Posted March 1, 2021 Author Report Posted March 1, 2021 Great info here, thanks all, will update once I get to the airplane. Quote
hypertech Posted March 1, 2021 Report Posted March 1, 2021 Not sure if its the same as the one that came on my ovation, but be careful when you take the bulb out. That colored lens will suddenly liberate itself from the wing tip and if it hits the floor it will cost you $40-80 depending on how good you are at ebay. 2 1 Quote
PT20J Posted March 2, 2021 Report Posted March 2, 2021 These aren’t cheap. Lots of folks are going to LED replacements. Just be aware that some LED bulbs seem to cause the Gear Down annunciator light to be dim all the time (if all nav bulbs are replaced with LEDs) because of interaction with the nav light circuit. Quote
Adi Posted March 2, 2021 Author Report Posted March 2, 2021 I took the old bulb out and confirmed that the filament is indeed broken, which is great news for me! The socket appears to be a GRIMES A-1825, but the bulb itself just says "G-22 SL" which doesn't get any Google hits. Here are the pics: https://photos.app.goo.gl/MvHAWMgCH3xYdTCn6 The bulb definitely seems very similar to https://www.aircraftspruce.com/catalog/pnpages/11-01964.php?gclid=Cj0KCQiAvvKBBhCXARIsACTePW8DLqaCPcY7osB0H_CSIOm9N94dzaRjYDia7Zaiaj0MvCDJ766jFrgaAok0EALw_wcB, however "A-1825" is not listed under the "Grimes P/N" compatibility table on this page. Quote
carusoam Posted March 2, 2021 Report Posted March 2, 2021 Grimes is probably the original light bulb manufacturer for the Wright brothers... If you can’t figure out the part number or get a replacement... Talk to Dan at Lasar... he is the Mooney parts guy guru... You might be the first person to ever wear out a nav bulb.... Best regards, -a- Quote
ZuluZulu Posted March 2, 2021 Report Posted March 2, 2021 1 hour ago, carusoam said: Grimes is probably the original light bulb manufacturer for the Wright brothers... If you can’t figure out the part number or get a replacement... Talk to Dan at Lasar... he is the Mooney parts guy guru... You might be the first person to ever wear out a nav bulb.... Best regards, -a- Nope, my green bulb recently burned out, so it does happen! 1 Quote
Adi Posted March 3, 2021 Author Report Posted March 3, 2021 Thank you all, replacement with a A-7512-12 was successful! 1 Quote
carusoam Posted March 3, 2021 Report Posted March 3, 2021 Great follow-up ADI! Best regards, -a- Quote
bradp Posted March 3, 2021 Report Posted March 3, 2021 I started putting an old pillow below fragile things that are likely to drop and be rendered useless. 2 Quote
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