Problem with light switch???
 

Hi, just had my MG ZT light switches converted to Blue LEDs... trouble is that now I have the switch back ( and this is the 2nd converted replacement for the original )... there is only 1 LED lit, which is on the headlight level rotor... In addition, as soon as you turn the switch for the headlights on, the whole instrument cluster and AC unit dim to virtually nothing and my CD / SAT NAV brightness fluctuates constantly. The dash dimming rotary control does not work, nor does the headlight level rotor.
I only sent of the switch facia for conversion, the main box remained in the car.
Has anyone come across this problem before, I don't want to buy another switch control box unless I'm sure the existing one is at fault... I am wondering if there is an ECU type problem communicating with the light switch pack?
All suggestions gratefully received,
Thanks
Phil:shrug:

Thanks to all who responded, finally traced fault tonight. Turned out that one of the links on the ribbon cable between the PCB and the headlight switch was broken. I had the circuit board out of its housing and saw what looked like a mark on the outer edge of the ribbon about 10mm from the PCB. Looked at it with a magnifier ( I am a bit old! ) and found a break. Pared back a little of the plastic on either side and put in a bit of wire to bridge the break and bingo ....everything fine again...
Very simple, but it's taken ages to find it!

Was it ok before the conversion?

Hi Phil... yes, all was fine, I was wiring in some foot well lights a couple of weeks ago, I had a fuse go, car wouldn't start, which turned out to be the rear fuel pump, and at the same time sent away all switches for conversion.... now I did try a new blue speedo unit to check lights were OK, ( I know it needs a T4 session before permanent installation )...which I initially thought might have been something to do with the non starting.... and because with no light switch for a couple of weeks ( long story ), I had to disconnect the car battery every time car was not in use otherwise the rear lights and side lights remained on all the time! Does this give any clues?
Thanks
Phil

I would back track what you did with the foot well lights and also check your fuses by removing them and testing each one, do not test them whilst in the fusebox as you will get incorrect results.

Fuses all checked individually, will have to check foot well lights at weekend.. They are run from the cabin light on the door open circuit, and earthed into the cig lighter. They operate correctly, but I'll disconnect and see if it makes a difference... has to be worth a try!!

Dont forget to check the LSM front panel has been reconnected correctly and the ribbon cable is fully home, its keyed so should only fit one way.

All checked, disconnected foot well lights, connections on LSM seem fine ( Not forgetting this is the second switch )... still the same problem. It's probably something stupid, but I'm at a loss!!

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