Good afternoon all,

 

Rather an odd experience for my Fabia VRS today... 

Update so far - Last week, driving to work for ~100 miles, the battery/charge light starts flickering then comes on steady.  This follows by the bulb fail light appearing (later discover fuse F34 has failed)  

Alternator presumed at fault, having measured output from it at ~12v, and across the battery at 11.8v (expecting ~14) with the engine running.

 

Alternator replaced with new 90A Lucas unit.

Battery/charge light remains, but output from new alternator now ~14v, at it and the battery terminals.

Battery/charge light clears once 5A Fuse F34 replaced... All is well and normal with the car for a week.

 

Today, a week later towards the latter part of the same drive, I notice the windscreen wipers are still running despite being off at the stalk.  Playing round with the stalk the results with the battery light starts flickering then remains.  Then the bulb fail light comes on. (Fuse F34 blown again on later diagnostics)

 

Assuming this perhaps is all due to the battery being completely knackered (I've never changed this in the 8years and 110k miles traveled since Ive owned the car) - I replace the battery.

 

On replacing battery, and replacing F34, the lights remain/wiper still running rogue but this time in a different pattern:

 

Headlights/Side lights on = No battery/charge light.

Headlights/Side lights off = Battery/charge light and sometimes bulb fail light (but it hasnt blown fuse yet..)

Rear wiper on, front off = Front wipers behave as requested (off)

Rear wiper off, front off = Front wipers run constant.

 

All the above seem very odd and I cant find anything similar searching the forum other than the battery charge light potentially being due to the alternator load wiper being at fault (Haven't yet checked this).

 

Anyone have any suggestions on the way ahead to fix this? From what Ive read if it was the alternator load wire, I'd likely see a traction control light too?

 

Many thanks in advance/enjoy the chaotic electronic goings on above!

 

Ben

 

Edited 27 January, 20251 yr by Clarke2744

Fuse 34, in a car with bulb failure warning, does the front left sidelight (direct) and the rear left one via bulb warning module.

Since you were seeing a warning at times when the fuse was intact, I'd suggest investigating the left rear light cluster. Don't be surprised to find moisture shorting connector pins, or evidence that it has been there. 

 

The battery light and wipers are controlled by the onboard supply control unit (in front of right knee in RHD cars, above accelerator pedal). If trouble remains once the fuse 34 thing is sorted, maybe try swapping in another of identical part number.

 

For info, the battery light working at all means the blue excitation wire for the alternator is intact.

You correctly state that if the load sense wire (the other, non-blue one) is broken on cars with ASR, you tend to get that warning light appear after 10 minutes running.

 

36 minutes ago, Breezy_Pete said:

Fuse 34, in a car with bulb failure warning, does the front left sidelight (direct) and the rear left one via bulb warning module.

Since you were seeing a warning at times when the fuse was intact, I'd suggest investigating the left rear light cluster. Don't be surprised to find moisture shorting connector pins, or evidence that it has been there. 

 

The battery light and wipers are controlled by the onboard supply control unit (in front of right knee in RHD cars, above accelerator pedal). If trouble remains once the fuse 34 thing is sorted, maybe try swapping in another of identical part number.

 

For info, the battery light working at all means the blue excitation wire for the alternator is intact.

You correctly state that if the load sense wire (the other, non-blue one) is broken on cars with ASR, you tend to get that warning light appear after 10 minutes running.

 

This is interesting - thanks very much for your reply.  I’ve just checked front & rear near side lights, no signs of corrosion or evidence of being wet on either. However the front side light isn’t working, the bulb is fine and having changed for a new one it still doesn’t work, whilst the fuse is fine. Not having a multi meter with me I can’t check too much until the weekend, but would this point at all towards the onboard supply control unit? 

No, I think that must be a wiring or connection issue.

Can you share reg number or VIN so that I can get a build date, please?

There are different wiring documents for pre and post-May 2004, and it would be good to know which was more appropriate to be looking at.

Reg private messaged to you - Many thanks.