Electrical problem with indicators.

The Left hand indicators on our 2003 discovery 2 td5 work fine. The right hand indicators don't work at all. Not with stalk switch, hazard switch or key fob. Tried connecting up a trailer board and exactly the same. Tried swapping the relays around in the passenger compartment fuse box and it had no effect. When the stalk is turned the green light on the instrument cluster flashes just once but none of the bulbs do. I haven't removed bulbs yet as too dark. What should be my next step? Thanks.

Two things to rule out: the IDM and the BCU, start with the IDM(interior fusebox) check for corrosion in it's plugs and if nothing visible swap it with a known good one ...disconnect the battery before you unplug it, if you swap it make sure the repacement was removed from a facelift and after the swap and battery reconnection turn ignition on II and let it so 5 minutes

sierrafery said:

Two things to rule out: the IDM and the BCU, start with the IDM(interior fusebox) check for corrosion in it's plugs and if nothing visible swap it with a known good one ...disconnect the battery before you unplug it, if you swap it make sure the repacement was removed from a facelift and after the swap and battery reconnection turn ignition on II and let it so 5 minutes

Click to expand...

Thanks. Do they come with the passenger compartment fusebkxes? Do they unplug like a relay?

IDM actually means the whole fusebox

sierrafery said:

IDM actually means the whole fusebox

Click to expand...

Thanks.

How would a fuse problem only take out one side?

It wouldn't, but the indicator flashing is controlled by the BCU and IDM.

The direction indicators and hazard warning lamp operation is controlled by the Body
Control Unit (BCU), Intelligent Driver Module (IDM) and two electronic relays in the
passenger compartment fusebox. The IDM and the relays are are an integral part of the
passenger compartment fusebox and cannot be serviced individually.

That is why I swapped the relays, in case one had gone. Also why the problem is so worrying.

sierrafery said:

Two things to rule out: the IDM and the BCU, start with the IDM(interior fusebox) check for corrosion in it's plugs and if nothing visible swap it with a known good one ...disconnect the battery before you unplug it, if you swap it make sure the repacement was removed from a facelift and after the swap and battery reconnection turn ignition on II and let it so 5 minutes

Click to expand...

Swapped the IDM today and I now have both indicators working. Thanks a lot. Also got lots aof spare fuses and relays.

Well done, i'm glad you escaped with the IDM and it wasnt the BCU cos in such cases it's a 50% chance for any of them

I always fear the worst. A bit of a scare though - the engine was immobilised. After switching off and on and pressing the fob buttons a few times, it cured itself. Thanks again.

Did you let the ignbition on II for 5 minutes after the swap as i told you? ...cos that's the trick to synk the immobiliser

No, I forgot that bit and dived straight in. I will definitely remember next time.

That's why it made tricks... yes, remember that cos this time you was lucky that you didnt end up immobilised for good, that 5 minutes ignition is necessary for the IDM and BCU to regain full digital data communication cos they are connected through a low speed data bus