Hornby Railroad Class 43 HST lighting

[Sir Topham Hatt]

This should be simple I thought  The Railroad class 43 is a great runner for the price and the shell, ex Lima, is a good one so for around £40-65 for a new one you can't go wrong..........

 

Though made in 2008 (I think) I managed to find two new ones in model shops around the country and bought two so that I would have two driven cars and decoders in both driving cars for directional lighting.  The models are DDC ready, but it appears only after a fashion as with the decoders fitted the white lights shine brightly from both front and rear cars at all times and are not switchable.  Of course, there is only a single white led fitted so I wasn't expecting a red lamp but I did expect to be able to swith the lights off / run directional whites. 

 

I removed the DCC socket board and was a bit surprised to find only the red/black/orange/grey wires fitted (no functions then) and also that pin 1 (marked on the board) had the grey wire attached, not the orange.  The red and black sockets both had 3 wires solderd to them, one from the front pickups, one from the rear and one which went to the small "lighting" pcb which sits just behind the drivers cab.  In small print on th pcb the wire tags showed TRK 1, TRK2, so logically unadultarated power from the track, be it 12v dc or 16v ac if DCC.

 

The orange and grey motor wires also go to the pcb to tags marked J1 and J2.  Two further wires run from the pcb to the motor, their tags are marked M1 and M2.  There is a normal supressor bridging the motor brush tags so I can only assume that the motor leads run into and out of the PCB to be treated to other power cleansing treatments?

 

Here is a small photo of the board.  Ignore the wire colours as the blue/white are leads to the motor!

 

 

I'm no electronics genius but I reasoned that what I was now about to do was safe. I unsoldered the black and red Trk1/Trk2 leads from the DCC socket board and resoldered them to the blue and white (or yellow) pin sockets so that the "lighting pcb" would now get a DCC function switchable 12v DC supply, just as the circuit would get if used in DC mode, but now directoinal/switchable.

 

I checked the sockets on my meter before replacing the decoder and there were no shorts.  Decoder fitted and back on the track I prepared myself for a pat on the back but...... a tiniest puff of smoke glided out from the decoder and that was that!

 

I rang Hornby for an expalnation of what the small lighting pcb actually did and was told I'd get a call back.  I backed this up with an e-mail.  That was on 1 May.  Frustrated I called again today but they are moving offices and would call back.  So, in the mean time, and aware that Hornby do not offer technical support if you are modifying their product (that is, changing it to work as it should have done when manufactured!?), can you electronics experts here help me out?   I'm guessing some of you will maybe recognise some of the components on the pcb and explain what they do.  My first instinct is to ditch the pcb and socket board and simply hard wire the decoder harness to pickups, motor and light leds via resitors (including a red one this time) but I don't want to loose anything on that pcb that could be doing something useful. 

 

In that good old forum cry for help - HELP!

[bgman]

Sorry to hear that. I too am not an expert, that said I recently hard wired a Trix loco which was wired in an unconventional manner ( I took it to my local model shop and both of us were in agreement with the wiring set up). I decided to track the pickups and make a note of them, then stripped out the original board completely. I hardwired all the relevant wires onto a new piece of pcb and put it on my programming track. Hey presto! In now works like a dream no suppressor etc or original wiring to be seen. Lights work ( original bulbs both back and forward as per any conventional loco ). I too used a meter to test for shorts prior to placing on the track. Don't know if this helps but I've hardwired quite a number of locos over the years in a similar fashion, sometimes using a resistor for LED's where required.

I have tried a "friendly" conversation with some manufacturers in the past and found it a total waste of time.

 

Good luck hope you find a solution.

[Sir Topham Hatt]

Thanks bgman.  Unfortunately, with the class 43 across the work bench in bits for the past couple of weeks and still no response from Hornby I became impatient and did it the way I know how - removed the 8 pin socket pcb and the 'lighting' pcb and hard wired a new DCCconcepts 4 function decoder in place. I'd still be very interested if anyone can explain why I had the problems described in the top post though.

 

I checked the smooth running of the chassis before wiring the lights and all was well so I still don't know why the motor wires went into the lighting board - maybe it does something in DC mode - and then fitted dual colour leds (white/red) to the inner pair of lights and bright white to the outer pair.  Yes, I know the reds are located in the centre of each 3 lamp lens but that's the lamp Lima/Hornby used to fix the lens in place and it really doesn't draw attention to itself.  The only problem left was to reverse the red/white so it showed correctly when you change direction, despite all the wiring conforming to the standard.  I recalled someone else had this problem on this site and sure enough his solution worked for me too.  So, all good, but as I said, I'd still be interested in finding out just what that pcb does!

[RJS1977]

Get rid of the socket altogether and wire the chip up directly like I did for someone a few years ago....

[Sir Topham Hatt]

See above!  That's just what I did and it works fine.  Just got an email from Hornby - they want a wiring diagram from me...... for their product!  Glad I didn't wait.  However, I will pursue the enquiry with them as I'm curious to how it will turn out. 

[RJS1977]

See above!  That's just what I did and it works fine.  Just got an email from Hornby - they want a wiring diagram from me...... for their product!  Glad I didn't wait.  However, I will pursue the enquiry with them as I'm curious to how it will turn out. 

 

Apologies - posts must have crossed!

 

Where I got really clever was discovering that if you strip the outer casing off a 9-way D-connector, it will fit through an HST corridor connection - I used that to wire both sets of power car lights (and, i think some interior lights in the centre coach) through one chip!