Common Maglite Defect?

I've owned at least a dozen different maglites over the years. At least 2/3 have developed the same.problem: if you tighten the tailcap all the way it won't light. Loosen it a quarter or half turn and it works fine.

What is the cause and cure (besides loosening the tailcap!) or this issue? It's annoyed me for years.

You're getting contact issues either where the cap meets the rear of the battery tube, where the spring sets in the tailcap, or spring pressure is causing you to lose the ground at the switch.

Clean all tailcap and battery tube contact points, Remove the switch boot, and tighten the ground screw.

Thanks for the suggestion. Because the symptom is always the same i thought the solution might be.

All lights that use the tightening/loosening adjustment scheme are prone to issues with too tight/too lose scenarios. Cleaning the contacts and making sure the contact paths are intact/secure is typically the way to take the slop out of the adjustment.

Despite being a life-long flashaholic I've never had this problem with any other brand. I have 3 maglites at home and all 3 have it. I don't see why my maglites would get dirtier contacts than all my other brands. No more maglites for.me!

Hmm.. interesting. I've never had this problem before and I've had a lot of maglites although to be fair I don't use stock maglites on a regular basis. Do you happen to live in a particularly corrosive environment e.g. near the sea?

What could be happening is that the bare aluminium contact points on the end of the tube and tailcap have oxidized to the point that it's no longer conductive and it's actually making contact through the threads which have worn through the anodise at 2 points that match up at that particular position. The constant rubbing from screwing in and out would be constantly cleaning off the corrosion at those points.

Try cleaning the contacts first and twist the spring round a few times. If that doesn't work, try sand paper on the tube end contact and a file on the cap contact. You need to be careful as it's easy to mess it up and scratch the light.

I doubt its the grub screw under the switch boot that is to blame but it won't hurt to make sure that its tight (don't over tighten it though).

If the mags have a tendency to be looser due to production tolerances, sure, they might be the only ones that had problems...its always question of degree.

I have some modded mags, and its not that the contacts get dirtier, per se, but, cleaning the contacts on lights that need help with the current paths tends to improve the current paths....same with the ground screws, etc.

This is why Cu tape, etc, is used sometimes to tighten up/improve the continuity of the connections.

In fairness my mags are my oldest lights however some have been that way for many years. Could just be corrosion. Waste basket is easier than messing with them with no certainty of success. If it had been an answer like "oh ya, that happens to all of them...it means u need a new spring (or whatever)" I would do it. I was thi king of buying some drop ins for them but I could buy a good xml P60 or even an entire flashlight for the cost of those drop ins.

I have two 6D lights from the late 90s. One of them does this. I've never really thought about lubing my threads, until I started buying batteries, chargers and lights in January and started paying attention to this stuff.

My caps always squeaked like a banshee, so I finally applied some synthetic lube to the threads and things work much better. I did clean them first with Iso alcohol.

Chris