I know this has been asked before but my keywords are just not producing results..

 

Car is an '08 diesel pre facelift vRS (BMN (PD170) engine)

 

With key in ignition on position, no lights are on. Fuel gauge not registering. Car doesn't turn over.

If I leave ignition on, power will come. And go and few seconds later.

If I catch it, I can turn the engine over.

 

The no lights, not starting thing has happened a few times over the past few weeks but now it seems it's a permanent fixture. Car is dead. And it's my missus' daily so I need to sort it asafp.

 

Read a couple of things about relays 40 and 460 being a potential issue. As well as a broken wire to one of the aforementioned relays (40, I think)..

 

I'm ok with very rudimentary electrics but that's about it. 

 

Anyone share an insight (urgently if possible) please???

if it's intermittent could a dodgy ignition barrel cause these faults 

16 minutes ago, Gissin said:

if it's intermittent could a dodgy ignition barrel cause these faults 

It seems exactly like that tbh. 

But for one thing. 

 

If I leave it sitting ignition on the dash lights randomly come on/go off. 

If they're on and I try to start the car they go off. Every time. 

 

I swapped the 2 460 relays this morning and things improved. 

Dash lit up immediately. 

Couple of problematic starts but then about a dozen perfect ones. 

 

Going to order 2 new relays from the local dub dealer. 

 

Don't know what else to do. 

1 hour ago, Evil said:

If I leave it sitting ignition on the dash lights randomly come on/go off. 

If they're on and I try to start the car they go off. Every time. 

The first line above says the ignition supply is intermittent

The second line I suggest is because you have to move the contacts in the ignition switch barrel and the worn contacts won't remake.

 

All of which points to needing a new ignition switch on the back of the barrel assembly.

There are videos showing how to do this and, from memory, seems easy.

 

Just found this: https://www.youtube.com/watch?v=KYVjVhGVQ68

 

8 minutes ago, pikpilot said:

The first line above says the ignition supply is intermittent

The second line I suggest is because you have to move the contacts in the ignition switch barrel and the worn contacts won't remake.

 

All of which points to needing a new ignition switch on the back of the barrel assembly.

There are videos showing how to do this and, from memory, seems easy.

 

Just found this: https://www.youtube.com/watch?v=KYVjVhGVQ68

 

 

Yep.. makes perfect sense (I think the failing relay scenario fits too, having read a few things in the last dozen or so hours)..

If it's that easy I'll change it anyway.. thanks.. off to find a part number.

 

Read another thread on here earlier that said the steering wheel needs to come off to get the cowling off. Not really up for that tbh... maybe a few year back but I really cba any more.

5 minutes ago, Evil said:

Read another thread on here earlier that said the steering wheel needs to come off to get the cowling off. Not really up for that tbh... maybe a few year back but I really cba any more.

 

If that is the Indian video then he overcomplicates and guesses.

5 minutes ago, pikpilot said:

 

If that is the Indian video then he overcomplicates and guesses.

 

Gotta say... steering wheel off to remove cowling seemed excessive but nobody called him out on it so I moved on.

New switch ordered (aftermarket, not genuine, should be here Monday).

Swmbo can use my car til then - it'll cost her a fair bit more in fuel but it'll get her to work and back for a few days.

Fingers crossed that'll be it .... thanks for the assist, much appreciated 👍

It sounds to me like a dry or fractured sodered joint on the instrument cluster, cheap and quick to remove the cluster and reflow the joints while waiting for the hopefully not required ignition switch.

 

If you dont want to do that then you could jump the ignition switch contacts to be absolutely sure that you are following the correct diagnosis.

 

You would need the key in the ignition as normal (turned to the correct position) for the immobiliser, all you would be doing is giving a helping hand to the suspected high resistance contacts.

3 hours ago, J.R. said:

It sounds to me like a dry or fractured sodered joint on the instrument cluster, cheap and quick to remove the cluster and reflow the joints while waiting for the hopefully not required ignition switch.

 

If you dont want to do that then you could jump the ignition switch contacts to be absolutely sure that you are following the correct diagnosis.

 

You would need the key in the ignition as normal (turned to the correct position) for the immobiliser, all you would be doing is giving a helping hand to the suspected high resistance contacts.

 

Have you had a set of mk2 clocks apart? 

And do you know what the ignition switch looks like? 

Yes and yes, why do you ask?

12 hours ago, J.R. said:

Yes and yes, why do you ask?

Because mk1 clocks are complicated, I'd hazard a guess that mk2 ones are worse... just identifying a dry joint would be a nightmare.

 

And, if I could work out which pins to short on the ignition switch, the logistics of shorting them out and plugging in the others while trying to start the car...... no, just no. It's a very small, very enclosed, socket with a similarly small plug. The potential for further damage....... 

 

While I really do appreciate the input, you've managed to increase difficulty astronomically.

I wont make the same mistake again.

New switch arrived, got it fitted and car fires straight up... 

Still got 2 relays arriving Tuesday because they're cheap and known to be twitchy.. 

 

Thanks for all the input (including @J.R.) I appreciate every reply..

 

Added a pic of how the old one came out, in spite of using picks to depress the clips.. 

The tracks clean up easily enough but for such a fragile part with the potential of bits taking flight its not really worth the risk unless you are stuck somewhere.

 

This type of fault is happening more and more where switches are no longer switching the load but just a small control current to the relevant canbus module which in turn operates relays, they dont exhibit symptoms of the contacts oxidising and once the signal falls beneath a certain threshold it is ignored by the recieving module.

Edited 4 September, 20214 yr by J.R.

Glad you took my advice and it is now working.