2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Odd electrical issues - '88 S4 Turbo II

Thread Tools
 
Search this Thread
 
Old Sep 14, 2012 | 01:00 PM
  #1  
88fc3sT2's Avatar
Thread Starter
Senior Member
iTrader: (1)
 
Joined: Jun 2012
Posts: 470
Likes: 0
From: Fort Lauderdale
Odd electrical issues - '88 S4 Turbo II

When I'm driving at night, I pop my lights on. I noticed that when I'm at idle, the gauges are very very dim. When I start driving, all lights that are on brighten up. I even hear the fuel pump sound like it's getting extra power. When I get back to an idle, the pump gets quieter, my lights dim down... it's just weird. But the odd thing is, my gauges don't even get that bright when I'm driving, it's still very dim. All the lights on it are good and I know this because out of the blue, they completely lit up for a quick moment and dimmed back down. Anyone have an idea of what's going on? I'm thinking it is a ground issue, but I don't know where any of my grounds are. Thanks
Reply
Old Sep 14, 2012 | 01:12 PM
  #2  
satch's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Jun 2005
Posts: 11,738
Likes: 16
From: tulsa,ok.
It's probably because your alternator is not producing enough voltage output. You have a Black cable connected to the alternator that is the output wire. Voltage measured on this wire should be 14.4 volts at all times while the engine is running.

Last edited by satch; Sep 14, 2012 at 01:31 PM.
Reply
Old Sep 14, 2012 | 01:33 PM
  #3  
88fc3sT2's Avatar
Thread Starter
Senior Member
iTrader: (1)
 
Joined: Jun 2012
Posts: 470
Likes: 0
From: Fort Lauderdale
Could be that, I'll get that checked even though it's pretty new.
Reply
Old Sep 14, 2012 | 02:06 PM
  #4  
satch's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Jun 2005
Posts: 11,738
Likes: 16
From: tulsa,ok.
The alternators you get at the local parts stores are mostly useless.
Reply
Old Sep 14, 2012 | 03:00 PM
  #5  
88fc3sT2's Avatar
Thread Starter
Senior Member
iTrader: (1)
 
Joined: Jun 2012
Posts: 470
Likes: 0
From: Fort Lauderdale
Well I just got everything tested, they're dumb tester said everything is good. Although, the guy did mention that the tester doesn't pick up on little things inside the alternator. Still debating whether it's a bad ground or not. I also forgot to mention that my right blinker blinks fast as if one of my bulbs were bad but they're both good. It's also pretty dim too compared to the left blinker which doesn't blink fast and is brighter.
Reply
Old Sep 14, 2012 | 04:39 PM
  #6  
texFCturboII's Avatar
version 2.0
Tenured Member 15 Years
iTrader: (17)
 
Joined: Mar 2007
Posts: 3,596
Likes: 2
From: Fort Worth, TX
Sounds like more low voltage, like satch said. Do you have a voltmeter? The tests they run at those stores are useless too and the results are just as easily determined by the behavior of the car. Re-doing your grounds is never a bad idea though, but I'd also start looking for another alternator. Time for an upgrade.
Reply
Old Sep 22, 2012 | 12:07 PM
  #7  
88fc3sT2's Avatar
Thread Starter
Senior Member
iTrader: (1)
 
Joined: Jun 2012
Posts: 470
Likes: 0
From: Fort Lauderdale
I'm such an idiot.... -___- I never realized there was a dimmer on the side of the **** for the lights.
Reply
Old Sep 22, 2012 | 12:11 PM
  #8  
satch's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Jun 2005
Posts: 11,738
Likes: 16
From: tulsa,ok.
Clean up your room. Now!
Reply
Old Sep 22, 2012 | 12:52 PM
  #9  
beefhole's Avatar
Boosted. I got BLOWN!!!
Tenured Member: 20 Years
iTrader: (29)
 
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
At idle, the stock system will drop voltage to the pump for emissions and fuel economy reasons.
Reply
Old Sep 22, 2012 | 07:33 PM
  #10  
88fc3sT2's Avatar
Thread Starter
Senior Member
iTrader: (1)
 
Joined: Jun 2012
Posts: 470
Likes: 0
From: Fort Lauderdale
Originally Posted by beefhole
At idle, the stock system will drop voltage to the pump for emissions and fuel economy reasons.
That explains a lot. Cause it is very obvious since the pump can very much be heard.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Th0m4s
Build Threads
25
Feb 26, 2019 02:04 AM
rexhvn
3rd Generation Specific (1993-2002)
0
Aug 19, 2015 02:59 AM
befarrer
2nd Generation Specific (1986-1992)
4
Aug 14, 2015 04:18 PM




All times are GMT -5. The time now is 09:24 AM.