Its alive!
After the tip to collar trick failing I was pretty certain my tuner was dodgy. I confirmed this further when the Sony Stalk I picked up on eBay didn't work either. So, I borrowed an original Empeg tuner. Plugged it in, and it all works straight away. Just like that.
So, turns out that the 'stalk' part of my PCATS tuner and my sisters PCATS tuner is faulty somehow.
Very interesting. I had pretty much the same problem as you and I put it all down to my eBay Autoleads adapter (I have a PCATS tuner too).
I had to use Hijack's IR_Translate to get things working. The Button Codes display was a great help in determining the values to use in IR_Translate. After a few days, some of the button's actions became erratic and I found that some of the codes returned by the buttons had drifted a little. That's how I left things 18 months ago and, inspired by the notion that my Autoleads adapter isn't necessarily faulty, I will have another attempt at getting it working soon.
This is how my IR_Translate ended up:
[ir_translate]
;; Volume Up / down
80000018=VolUp,VolUp
80000037=VolDown,VolDown
;; Map directional buttons
80000016.LT=Player.N,Top.LU,null ; Top button long press: Tuner active, switch to player
80000016.L=Radio.N,Top.LU,null ; Player active, switch to Tuner
80000016=Top
80000035.L=Bottom.L,null ; Long press of bottom button = toggle visual/info
80000035=Bottom
80000031.LT=B9460A.L,null ; In tuner, long press of left scans back
80000031.T=20DF10 ; In tuner, left seeks back
80000031.M=PrevTrack.N,Left.U ; In player, track-. In menu, left
80000013.LT=B9460B.L,null ; In tuner, long press of right scans forward
80000013.T=20DF11 ; In tuner, right seeks forward
80000013.M=NextTrack.N ,Right.U ; In player, track+. In menu, right
Btw: does my PCATS tuner really give me better reception than my original tuner, or is it the case that the signal meter on the original one actually works as opposed to the PCATS one being stuck on max?
I find that anything less than a full strength signal display coincides with poor reception.
Going slightly OT, another problem I have had since building/installing my tuner is that the AF (Alternate Frequency) mode keeps re-tuning from a good signal to weak/marginal signal (3.00a11). This happens a few times/minute so I keep AF turned off which is a pain when driving long distances.
I need to dig my tuner out from the depths of my dash and re-check the coax lead's grounding - I might not have bound the earth connection as well as I should have.
I also have a spare (unbuilt) tuner kit and this thread has enthused me enough to get it assembled so I can swap it for the one I'm using now. Thanks for the 'prod'!