OBC illumination?

[eko]

Fitted a 13 button one in my car ages ago.
At the time I couldnt remember which pin in the accessory socket to plug onto so left it off till I found out.
Now since fitting the display alway goes out when I switch the lights on,I just assumed this was down to the plug I left off the accessory socket.
Well clearly not as ive now connected this up to the right pin and it still goes out when lights on.
Buttons light up fine with the lights and the display is nice and bright with lights off.

I thought a blown lightbar would fail too display with or without lights or am I wrong?

[daimlerman]

OBC display will dim when the main light switch is operated.At a guess,your OBC is failing to dim....just going out completely.
No idea how to fix it,though!

[Brianmoooore]

OBC doesn't connect to the accessories socket at all. All its supplies are via the yellow socket on the instrument cluster.
The OBC loom has connections to the accessories socket, but these are just for the 'CODE' alarm horn.

[eko]

OBC doesn't connect to the accessories socket at all. All its supplies are via the yellow socket on the instrument cluster.
The OBC loom has connections to the accessories socket, but these are just for the 'CODE' alarm horn.

I did fit the full kit including the code/alarm box etc so explains my connecting up that plug then
Any ideas on the illumination then Brian?
Im not convinced its the lightbar which would probably suggest faulty OBC display unit or dodgy Si board in my clocks perhaps?
Although the dash all functions as it should.

[Rav335uk]

Are your dash lights Dim??
I.e the light knob turned down??

Can't remember if this dims the OBC too.

[e30topless]

bad earth ?

[eko]

Dash lights are fine Rav.
Earths for the OBC are bolted to the original stud provided.

Worth mentioning ive fitted loads of OBCs and havent yet come across this problem so hopefully not something stupid ive missed
Although not really rocket science to fit are they!

[Brianmoooore]

Earths are also nothing to do with the OBC functions. Yellow on the cluster and green on the OBC is all that needs to be connected for everything on the OBC to work fully and properly, except for the CODE alarm/immobiliser and outside air temp.
This has to be an internal fault in the OBC itself. When 12 volts appears on the grey/red between the yellow and green plugs it does two things - illuminate the buttons on the OBC and reduces the voltage to the light bar. Something is wrong with this latter function, and the voltage is being turned off rather than reduced.
A simple 'cure' would be to cut the grey/red wire, but this would lose the button illumination.
A thought: Have you checked that the light bar has 'proper' bulbs in it and hasn't been converted to LEDs? It's possible that LEDs could drop below their minimum voltage if too high a value had been chosen for the current limiting resistor.

[eko]

Think ive got a spare display unit which ill plug in and try.
Lightbar is OEM.
Ill try the display and report back