TLS drop in not working in 6P

[toothy1!]

Can't quite figure this out. I have a TLS drop in for Surefire 6P. At first I tried it on a 6P LED body and the TLS bulb and TLS switch worked fine. Then, trying it out on a 6P body I wasn't able to get the drop in to operate. The switch seems to screw on a bit tighter on the 6P vs. the 6P LED but it seems to screw down all the way. The standard P60 Surefire bulb and switch works fine on both the 6P and 6P LED bodies. Any suggestions on why it isn't working on the 6P?

 

[greenpea76]

I've had issues with the springs on aftermarket p60 compatible modules. Usually the ground spring is the culprit. Maybe try stretching it a little so that it ensures contact with the non anodized portion of the body? The positive (center spring) can also be too short at times and result in not contacting the positive terminal on the battery. Sometimes you may just have to "enlarge" the center spring to contact the body.
I wouldn't stretch this too much as it may cause an unstable condition once depressed and may come in contact with the negative spring causing a short. Are you having to use an adapter between the body tube and head? If so, the spring will likely be too short. I've had some experiences with that happening and ended up with finding a longer center spring or modifying both springs all together for them to fit.

Its a bit frustrating as results vary and be very specific to your combination of parts. Hope this gives some insight on what to try.

 

[Justin Case]

If the 6P is an older generation version, then that's the issue. There are slight dimensional differences vs. the current version (as exemplified by the 6PL) and the TLS tailcap is having trouble making electrical contact with the bare aluminum face of the battery tube. The tailcap runs out of travel before it makes electrical contact with the battery tube.

Fashion a metal spacer out of a bent paper clip. Drop it into the tailcap onto the silver metal retaining ring and then attach the tailcap to the flashlight. The spacer should help to complete the circuit. Then go out and make a fancier spacer.