Disco 2 TD5 No indicators or hazards

Hi everyone,
I have a problem with having no indicators or hazards on a 2004 disco TD5. The light comes on the dashboard for one flash then nothing but no lights actually come on. I've tried a few things but not got any further forward. i swapped the internal fuse box with IDM off a 2000 v8 which i also own that i know works. Still no indicators or hazards. Now im not sure if there different. I know there different part numbers which makes me think there different but they look the same. i had a hawkeye plugged in and the BCU registers when the indicator is switched left but not right. I also cannot get the lights to come on with the hawkeye. I checked the earths... well the ones i could find but still nothing. Iv even put a multimeter on the indicator relays which are reading correct. Does anyone know what else to check or is it a case of replacing the BCU and getting it coded?

Cheers

Dan

Hi, first of all the IDMs are not 100% compatible between facelifts and earlyers but IIRC on the indicator's circuit might be the same so you can consider it ruled out, put back the original and replace the BCU to rule that out too... for the indicators circuit no need for any programming just let ignition on 2 for 5 minutes after the swap then turn ignition off and push the hazard switch ...if the hazards will work it means the problem is with the BCU so you can put back the BCU on the V8 and buy one for the Td5 which then will need programming.... if no change with the BCU swap we'll speak then cos it's feckless to chase other issue while the BCU is not ruled out

BTW, are you sure there's no other issue beside the indicators ?

Hi, swapped the BCU's over and still nothing! I havent encountered any other issues just the indicators and hazards.

Swap the stalk to rule that out too and if still no joy i'll tell you more... do you have RAVE ? By your first post i hope you checked fuse F14 engine bay though ?

sierrafery said:

Swap the stalk to rule that out too and if still no joy i'll tell you more... do you have RAVE ? By your first post i hope you checked fuse F14 engine bay though ?

Click to expand...

Swapped the stalks and still no joy. I do have RAVE. I did check fuse F14. I checked that first as I hoped it was that.

OK, if you remove a relay and measure for voltage between earth and the cavities do you ge 12V in two of them?

sierrafery said:

OK, if you remove a relay and measure for voltage between earth and the cavities do you ge 12V in two of them?

Click to expand...

Measured on battery shade over 12v. Measured at fuse F14 is the same. At the both relays its 9v at one of the larger pins(both relays)

So we are getting close to something as you should get 12V in two cavities at the relays which is coming direcly from F14, tha 9V is a return through the IDM, can you see the markings near the relay's legs to which one goes that 9V? also are you familiar with electric diagrams ?

I cropped and edited the relevant part of the diagram(the other relay is in parallel with this so the feed should be the same), if no 12V there(to terminals 86 - 87) it can be interruption on that path within the engine bay fusebox or on the wire.

...

sierrafery said:

I cropped and edited the relevant part of the diagram(the other relay is in parallel with this so the feed should be the same), if no 12V there(to terminals 86 - 87) it can be interruption on that path within the engine bay fusebox or on the wire.

...
View attachment 199847

Click to expand...

So the pins marked in red are approximately 9.6v ignition in or off. I hope this helps

Others have found the fault to be within the hazard switch itself. Tested everything, couldn't find a fault but changing the switch solved it.
Just saying!!

Not too good, it seem that it's a voltage drop on that path but this would give different sympoms , just confirm the folowings:
1. did you let the replacement BCU 5 minutes with ignition on 2 before you checked?
2. it behaved exactly the same like the other so did you get one flash on the dash?
3. do you ge that flash with the hazard switch too ?
4. when you swapped the fusebox did you follow the same procedure with battery disconnection and 5 minutes and it behaved exactly the same like the original ?

this is a hard to troubleshoot fault especially like this on a forum so every small detail is relevant

Stanleysteamer said:

Others have found the fault to be within the hazard switch itself. Tested everything, couldn't find a fault but changing the switch solved it.
Just saying!!

Click to expand...

It's first time i hear about that on a D2 but it can be ruled out easy by unplugging the switch and see what happens... a stuck closed switch might cause such symptom maybe

sierrafery said:

It's first time i hear about that on a D2 but it can be ruled out easy by unplugging the switch and see what happens... a stuck closed switch might cause such symptom maybe

Click to expand...

So managed to find the fault. It was the Purple/brown wire underneath the fuse box in engine bay where it goes into the loom. It was severely corroded but just to say held together which is why we were only getting 9v. Cut the corrosion out and soldered a new bit of wire back in its place and everything works perfectly.

Thank you so much for your help @sierrafery. I don't think i would of found it without your advice!

I have also heard that about the hazard switch as well @Stanleysteamer. Not sure about it though because im sure that used to be a fault on the disco 1.

Dan simpson said:

So managed to find the fault. It was the Purple/brown wire underneath the fuse box in engine bay where it goes into the loom. It was severely corroded but just to say held together which is why we were only getting 9v. Cut the corrosion out and soldered a new bit of wire back in its place and everything works perfectly.

Thank you so much for your help @sierrafery. I don't think i would of found it without your advice!

I have also heard that about the hazard switch as well @Stanleysteamer. Not sure about it though because im sure that used to be a fault on the disco 1.

Click to expand...

@Dan simpson you're probably right, I'm not sure which Disco I heard it about, just thought it worth mentioning as you never know!
Anyway, really pleased you found the fault. High five to @sierrafery

Dan simpson said:

So managed to find the fault. It was the Purple/brown wire underneath the fuse box in engine bay where it goes into the loom. It was severely corroded but just to say held together which is why we were only getting 9v. Cut the corrosion out and soldered a new bit of wire back in its place and everything works perfectly.
Thank you so much for your help @sierrafery. I don't think i would of found it without your advice!

Click to expand...

Welcome and well done... i've been thinking harder and i was up to recommend you to lift up the engine bay fusebox and measure on that path but it seems you figured it out already... i'm glad it's sorted