Sidelights not working

[davelowe]

Whats a UCH ?

Alan

It's the French acronym (Unite de Commande d'Habitacle) for the circuit board that controls the interior lighting / switches and other things. AKA interior multiplex module - behind / above the glovebox.

[Nige]

If this is a universal part....could you not of perhaps obtained from a breaker and got a professional mechanic to fit????

£350 is alot of money just to get working side lights...i know they are legal and required....but i guess you will get a warranty.

[davo748]

Hi ,i now have a smilar problem, the illumination for the radio, heater controls and cigar lighter are not working, the nearside rear light not working and front nearside side light not working.

I do have illumination on the dashboard console, windows and roof switch.All the fuses gave been checked and no power getting to the rear light. I had an ex Renault mech look at it and is stumped. I read your thread and it sounds like i might have a UCH issue. Did that resolve your problem?

Thanks

[baz_esq]

I have this same problem no sidelights, no tail lights, no number plate lights and no central console (lighting around the CD player and the fans). Does anyone have a suggestion or the wiring plans for a 2003 1.4 Renault Megane? I'm living in hope that it isn't the interior multiplex control module. Any advice very welcome!!!

[davelowe]

This will sound obvious, but there are three fuse areas, with varying relevance and difficulty of access. The easiest is to the side of the glove box. Remove each fuse 1 at a time, replace (or check for continuity), test and put back. Next, check the fuses on the battery +ve terminal. Measure the voltage with one probe on the -ve terminal and the other on the wrong side of the fuse (if you see what I mean). Next up are the hard to get at ones near the ECU. For some reason (at least on my car - the 1.9dci 2003) this fuse box is basically upside down and much air intake pipework must be removed for access. It's a big mess of relays and fuses. Good luck with that.

On another note, the UCH might or might not be knackered. Water has been known to get inside the bulkhead to which it is fitted. Thus corrosion or a bad connection might be the problem. To get access to it, you need to remove the glove box. Open the glove box door and remove around 6 torx screws (one is hidden behind some trim - they are not all obvious). Pull it forward and out of the car. The box that you can see with a wiring harness attached is the UCH. Disconnect the battery and then inspect it. If you are feeling brave, and are certain it is to blame, try opening it up. I think it contains fuses - it certainly contains relays (you can hear it click when the rear wiper is operated, for example). Repair may be possible.

[kenspark]

I am having similar issues with my Megane 1.5 DCi 80, 2003 (3 door).

The central console illumination has stopped working, and will on occasion miraculously switch on, and then, maybe after ten minutes, switch off again. I could probably live with this, but the interior overhead light (courtesy light) that is supposed to switch on as any the door is opens has stopped working. The two reading lights either side of the main light have also stopped working. I checked and it’s not the bulbs. It’s a real nuisance on these dark mornings. The glove comparement light and boot light have also decided to stop working. Everything else is fine.

I checked all the fuses in glove compartment. I haven’t had a chance to check the hard-to-get-at fuses in the engine bay. Has anyone else had similar issues. Is it likely to be a UCH (Multiplexer) issue?

What does anyone think? These small problems are a pain in the ass.