A8 Parts Forum  

Go Back   A8 Parts Forum > A8 D2 > D2 - Everything else

D2 - Everything else Anything that doesnt fit elsewhere

Reply
 
Thread Tools Display Modes
  #1  
Old 20th October 2020, 11:34 PM
Nognar Nognar is offline
Senior Member
 
Join Date: Jul 2017
Posts: 244
Default The Red battery light of Joy

Driving the S8 this evening and having a great drive in a wonderful car.

On the way home the red battery light came on that is on the rev counter. Most odd I thought as the car is going well and its got a new battery in the back.

Stayed on and I was thinking hello is this an Alternator problem....

Driving through Cheltenham and more warning lights came on, dash dimming, battery light on the DIS, gearbox goes into limp and yes the poor old battery was clearly being drained and not charged. Luckily got it just to a friends house and parked it up and I can worry about it tomorrow. So its either going to be an alternator failing (was working fine) or its thrown the belt due to a grumpy tensioner.

I mean I cannot be too hard on the old girl it is 18 years old and done over 200k so the occasional old part is allowed to wear out!
__________________
--
2001 Audi A2 1.4 SE - Jaipur Red Pearl
2002 Audi D2 4.2 S8 - Ming Blue Pearl
2002 Audi D2 2.8 A8 QS - Audi Silver
--

Last edited by Nognar; 20th October 2020 at 11:45 PM.
Reply With Quote
  #2  
Old 21st October 2020, 12:23 AM
steamship's Avatar
steamship steamship is offline
Senior Member
 
Join Date: Jun 2013
Location: Londonderry, Northern Ireland
Posts: 2,931
Default

Quote:
Originally Posted by Nognar View Post
its got a new battery in the back.
First thing I'd check is the battery terminals to ensure they are fitted securely, and you don't even get your hands dirty.

Next would be a visible inspection of the connection block on the front drivers side chassis leg to see if there's a buildup of crud.

Failing that, await an answer from MJ
__________________
2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds
Reply With Quote
  #3  
Old 21st October 2020, 03:38 AM
spannerrash spannerrash is offline
Senior Member
 
Join Date: Dec 2016
Posts: 399
Default

Beg, borrow, perhaps not steal a multimeter from someone, put it on volts and put the leads across the battery terminals. Start the car and check what voltage your alternator is putting out. Quick and easy test. Should be about 14.4V. If it's low, and I suspect it will be, I'd then repeat the test at the terminal box in the wheel arch but place the meter leads between the big battery cable and the chassis. You will have to probe around a bit on the battery cables because it is possible that a bad terminal box connection will give a poor result on the long cable going back to the battery and a good result on the shorter cable. This would actually be a good thing as it would indicate a bad connection in the box. An easy ish fix.

If all is well here then you need to be checking out the alternator. Could be poor connection's there or brushes worn-out.

Brushes are easy to replace, no soldering required but I am unsure if it can be done with the alternator on the car. Not sure if there is enough room to remove the rear cover and air duct to get access.
Reply With Quote
  #4  
Old 21st October 2020, 06:37 PM
Nognar Nognar is offline
Senior Member
 
Join Date: Jul 2017
Posts: 244
Default

Thanks for that, yes have a multimeter as tested it a while back when I had a Yuasa Silver battery causing no end of problems.

Got the car back home tonight which is good news.

Put a spare battery in and started OK, still had the red battery light on the dash. Then the car was running rough and really rich, then it died...

.....and would not start again even after a period of time to see if was flooded

Called the RAC and said they would be about three hours!!!!!!!

This would normally be the end of the story but I disconnected everything, let is reset and then forced the car to start on LPG. Drove home no problems (red battery light still on of course).

Ahhh all in the pouring rain also.

Never mind, Hooray for LPG
__________________
--
2001 Audi A2 1.4 SE - Jaipur Red Pearl
2002 Audi D2 4.2 S8 - Ming Blue Pearl
2002 Audi D2 2.8 A8 QS - Audi Silver
--

Last edited by Nognar; 21st October 2020 at 06:41 PM.
Reply With Quote
  #5  
Old 21st October 2020, 07:06 PM
MikkiJayne MikkiJayne is offline
Senior Member
 
Join Date: Jan 2012
Posts: 5,017
Default

You may have killed the fuel pump running it low on volts. I've seen that before when the alternator has died and the car was driven until the battery went flat.

The alternator does need to come off to replace the regulator so at that point its as easy to just fit a recon, although if you can afford to have the car offline for a few days a regulator is a cheap enough to try. If you buy a recon, make sure its for a V8, not a V6. A lot of places say they are the same, but the rear air ducting is different. The V6 alternator will bolt up but the ducting then won't fit.
Reply With Quote
  #6  
Old 21st October 2020, 07:27 PM
Nognar Nognar is offline
Senior Member
 
Join Date: Jul 2017
Posts: 244
Default

It can be on the drive/ in the garage for a while so I agree I will take the alternator off and try a regulator first of all.

Then look at the fueling, it could well be the pump has decided to die at the same time just to help matters! I will give it a tickle with VAGCOM to see if it throws any light on the matter.

Does anyone have the part number for an S8 Regulator?
__________________
--
2001 Audi A2 1.4 SE - Jaipur Red Pearl
2002 Audi D2 4.2 S8 - Ming Blue Pearl
2002 Audi D2 2.8 A8 QS - Audi Silver
--

Last edited by Nognar; 21st October 2020 at 07:50 PM.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 07:22 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.