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SDCC Class 43 HST Lights

Sorry to resurface an old thread, but I too am having similar (but not identical) issues with a recently -acquired DCC sound HST set.

Both the power cars are fitted with a TTS sound decoder and speaker. The unpowered trailer car lights are working perfectly as expected - turning on with function 0 and changing direction.

However the tail lights in the powered car come on when it is placed on the track (irrespective of whether function 0 is on or off). When I turn function 0 'ON', these lights go off, however the trailer car lights (which are working correctly) come on. I can manage to get both ends to light at the same time by putting the trailer car on the track, switching on function 0 and then placing the power car on the track. The power car, however, will not switch from showing tail lamps to headlamps. There is the slightest of flickers from the headlamps and cab light when the direction switch is pushed, but nothing more.

I've read through as many of these related threads as possible and tried the following, but to no avail:

- Resetting both decoders to factory settings by setting CV8 to '8' as per the Hornby TTS instructions.

- Checked CV29 to ensure correct speed steps selected

- Changed reverse direction in CV29

All other functions and motor control are working fine, but I've run out of things to try to rectify this.


Any help appreciated!


13366 posts

Community Moderator

Sounds like a wiring fault in the powered car.


If under warranty I would send it back.


If not under warranty then I would be looking for solder bridging problems on the pcb that has the decoder socket or a misllaced wire to the lights.

Halton Brat - Running Win 10, 64-bit - RM (Pro-Pack) with Elite as Controller-A, Select as Walkabout and E-Link as Controller-B - Locos are mostly TTS. http://www.halton96th.org.uk/robs_rails.html


1135 posts

I think the issue with this, is there are multiple types of HST, not helped by Hornby.  The newer Railroad HST from what I gather from posts (my one is old and I had to add DCC sockets) has the lights on permanently, so I think that explains many of the issues. You can do what ever you want to the decoder, but it is not going to change that. What you need to do is rewire the DCC socket so they are controlled by the decoder. I think it would help a lot if people explained what level of HST they have.

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