Yes I did try to jump the tail-cap and still nothing (I just used a screw to do it with).
Hey Cop,
You can reuse the spring if you like, but try and be careful when desoldering it and then soldering it to the replacement driver. If you get them to hot, you can anneal them (melt them) rendering it useless. If you’re going to perform these types of mods, it’s a good idea to get some spare springs from either IOS or Fastech in various sizes and keep in a spare parts bin.
I don’t have a J18, so you’d have to wait for someone else to chime in and answer your other questions.
Here is a link for a spring assortment.
http://intl-outdoor.com/goldsilver-plated-springs-for-drivers-and-switches-5-pcs-p-325.html
Here is a link for some rubber boots.
http://intl-outdoor.com/components-rubber-boot-c-57_115.html
Johnny, had some time to look at my J18 and refresh my memory on this... For the center spring, I used a good qual silver tinned spring, little over-sized from stock but works well, but of course you could xfer the stock spring. If you notice, the stock driver has a really wide ground contact on the spring side - this I think is for proper contact for the brass retainer ring assembly. The new IO driver (or KD) doesn't have anything near that wide - it just has 4 contact pads (see the IO product pages for a photo of what I'm talking about). That big spring, that it looks like you soldered, I ignored but still use it. Once the retaining ring is screwed down, the retaining ring itself makes contact on the board. So, I widened the contact pads by adding small pieces of copper tape next to 2 of the pads, and soldering them to the adjoining pads. Now, I can't recall if this actually fixed the problem or not.
So what you can do to test this is with the batt tubes removed, stack 2 batts on the driver spring, and use a jumper wire (I use 12 gauge stranded wire) to go from the batt neg down to one of those contact pads on the driver. I just did this myself and it lights up the light, so should work. Your mod of soldering that big spring may be doing the same thing, I'm not sure, but I took a different approach of making sure the brass retaining ring makes strong contact with those pads on the driver.
Tom, thanks for taking the time to pull apart your light to help….
I gave it another try tonight… I removed the large spring, soldered some copper tape to one of the pads, stacked 2 batteries together like you said on the center spring and put the copper tape straight to the battery negative… the light gave me a quick flash… then nothing…
ended up removing the spring, soldering all 4 pads together, and reassembling… nothing…….
One thing I did notice…
18650’s… if I put the batteries into the flash light and jump with a screw/clip at the end to bypass the tail cap… I get a small spark… If I use the 22650’s… I get a bigger spark… so the driver is trying to pull power…. just not driving the lights.
At this point, i’m starting to wonder if I
a) got a dud driver.
b) got a huge dud light.
c) really suck at modding lights… hahaha…
Oh boy, running out of ideas... Maybe it is the light since this is the 2nd driver - maybe blown emitter? Can you check the emitter wiring?
It actually sounds like when I upgraded my AK-47 with the KD driver and tried using my Trustfire 5000mAh cells. They didn’t have the power to get the light to work and would only flash for a second.
yup, sounds like the same problem i had when i tried putting 3x18650 in my modded ak47. bright flash just like you mentioned.
but i just kept playing with the switch , tried switching modes lots of times, then eventually low was able to come on. but everytime i tried switching to a higher mode, bright flash and then nuthing.
but when i switched over to some 26650’s the problem went away. so if i was thinking positive, id say its the batteries. but thats a very expensive risk to take to buy some better 26650’s and the problem sstill exists.
but thats wierd, tom e used the same batteries in his and it works, so i dunno now.
Tom, how do you take apart the light to get to the emitters? I don’t “think” that’s the problem as the light was working before with the stock driver (just it was really dim).
As for not enough power from the batteries…. I have to clarify that I only saw the flash once or twice… during a course of 40-50 try’s…. and it was not at “full power” as I would have expected.
When I modded a small sun zy-t13 a few weeks back (added a pot)… I had the “bright flash” when the pot was turned up to high… I remembered that flash was at “full power”.
1)Unscrew the head.
2)Unscrew that backing plate.(that copper plate with 2 holes at side)
3)Pull out drive- shake it abit or pry out with little force if it is stuck.(Mine just rest there)
4)You should see 2 + screws inside the head, take it out. It is screw to lock the reflector.
5)Anti clockwise open the top “bezel or crown”? o-ring & glass will come out.
6) With a little tug, that reflector will come out, exposing the emitters & wires within.
ok… quick update… I don’t think it’s the emitters or the wiring…
Reason is that I put the stock driver back in and the light works again (like it did before I yanked the driver out).
What I mean is…. the light will turn on, all the modes work… looking at the head, all the led’s do light up…. the problem now is that it’s very dim (hence the original reason I yanked out the driver).
I mean… on high…its not much brighter than my single R5 flashlight with a 14450……….
I wonder if it could be that your flashlights emitters are connected in parallel instead of series? This could explain the fact that it works fine with the original driver. Could you take the reflector apart and take a photo?
Pokasaha, it’s funny you mention that. My Skyray 9x T6 light is wired 3s3p and my Trustfire AK-47 is wired fully series. When I tried to use the Skyray driver in the AK47, the light wouldn’t work. I was sure the grounds were in proper contact, but I came to the same conclusion with my lights that perhaps the drivers were not compatible due to different wiring. Although Jonney’s light is a Trustfire J18, it’s not unreasonable to think the drivers are not compatible. I’d like to confirm this somehow.
I’d guess that the drivers are not compatible. Emitters in 3S3P config are driven around 10V. Emitters in 9S1P are around 30V. I doubt a driver designed for one of these general voltage ranges (8-12V and 25-35V) is going to be OK with the other range.
Your solution would be to rewire the emitters to match what the driver should have for a load.
Thank you Relic38, that just answered a lot of questions I’ve had.
Yeah, exactly. And this is why I ask. I’ve just ordered this torch and a driver and would like to know if they are compatible. If there is this normal wiring, these combined parallel/series solutions are ok but if the leds are put on a circuit board as in my friends torch I’m in trouble.
If you ordered the TR-J18, that is the right driver, 7 LEDs. The AK47 is 9 LEDs.
Yeah, I’m just concerned that are some of these TR-J18 wired differently since there seems to be these not getting on issues and also you can see that there are several models of this lamp sold. You can tell it from the differences in the body.
I managed to take my j18 apart and can confirm that the led’s are wired in series.
Thank you mate. 
This is good to know.
Update, with nothing to loose, I decided to play with the driver a bit.
The J18 driver I got looks almost the same as the ak-47 driver found here
and looking at the post by richie, he mentioned that one of the resistor was loose.
Well, I am not sure if mine is the same, but I do not have a resistor on that far spot…… does not even look like anything was there to start with (this light did work properly in the beginning tho).
Anyhow, I got my 20 ohm trim pot I had left over from modding my small sun zy-t13… soldered it into the spot, and just played with it. Turning the trim pot I can make the flash light brighter… up to a point…… once you pass this point the flashlight will give you a very bright flash then shut off…
Using 3 cells, I just tuned it until I got the max brightness without getting the bright flash followed by nothing……
To be honest, I do not think this is a proper fix. The light is still not as bright as it should be (I am showing just a hair over 2 amps draw at the tail with 3 cells… not sure what this works out to be) and the driver gets HOT. I mean that round coil on the driver gets up to ouchie temps in about 2 seconds when I was holding it.
What I can see is that, I think I do in fact have a driver problem… or a really bad battery problem… haha…
Jon.