|
|
|
|
| Author |
|
|
Registered
Join Date: Feb 2005
Location: Sacramento
Posts: 587
|
Alternator light not on when starting.
Hello all,
I have an 83 SC. for the past week, I have noticed that my alternator light on the oil gauge does not turn on when I turn the key prior to ignition. I know that it usually lights up when I did that. Not sure if this is something I should take notice of. It is an indication of an alternator going bad. I'd thought that when an alternator goes bad that the light would light up and not the opposite. I've also noticed erratic tachometer intermittently. surging from 3k to 6 and back and then would settle down to normal. Right now, I have no starting problem and the car seems to run good. Then again, I'm hesitant to take it on a long trip. If it's the alternator not charging then the car would eventually die on a long trip. I use it for commuting and it's 11 miles each way. so I am assuming that that is not a long enough drive to totally drain the battery. Any insight to this observance is greatly appreciated.
__________________
Carl, |
||
05-15-2009, 07:26 AM
|
|
|
GAFB
Join Date: Dec 1999
Location: Raleigh, NC, USA
Posts: 7,842
|
Alternator light may simply be burnt out - try swapping it out. Happens all the time.
__________________
Several BMWs |
||
|
05-15-2009, 07:32 AM
|
|
|
I would rather be driving
Join Date: Apr 2000
Location: Austin, TX
Posts: 9,108
|
Pull the bulb and test. Then check for continuity between the blue wire in the dash and the blue wire at the 14-pin connector in the engine compartment.
If the bulb is good and you have continuity then the alternator is likely bad. I just went through this in my car a few weeks ago.
__________________
Jamie - I can explain it to you. But I can not understand it for you. 71 911T SWT - Sun and Fun Mobile 72 911T project car. "Minne" - A tangy version of tangerine #projectminne classicautowerks.com - EFI conversion parts and suspension setups. IG Classicautowerks |
||
|
05-15-2009, 07:50 AM
|
|
|
Registered
|
Erratic tach is a sign there's potentially something wrong with your electrical. In my case it was a loose wire grounding out (bad alarm install
 ).I'd check the bulb first, but don't be suprised if your alternator goes sooner rather than later. One safe check would be to measure the voltage across your battery. Engine off should be around 12 (12.6 for fully charged battery). Engine running you should get over 13V. If you aren't, your alternator isn't doing its job or you have a short somewhere.
__________________
Don't Lift... Don't Lift... Don't Lift  '75 Targa in "Arrest Me" Red, 3.0SC ('79) engine, Bilsteins, Turbo Tie-rods, SSIs into 2-1 M&K muffler... and looking for my next upgrade. |
||
|
05-15-2009, 09:50 AM
|
|
|
Registered
Join Date: Apr 2009
Posts: 22
|
In many older cars, the indicator bulb is part of the charging circuit. If it is not on the car is not charging. Could be alternator, wiring, or bulb if the SC is of the older charge circuit style.
|
||
|
05-15-2009, 10:48 AM
|
|
|
Moderator
Join Date: Dec 2001
Posts: 9,569
|
Quote:
__________________
'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
||
|
05-15-2009, 11:13 AM
|
|
|
|
Registered
Join Date: Feb 2005
Location: Sacramento
Posts: 587
|
Thanks for your quick responses.
For an update, I charged the battery overnight and this morning, I check by turning the key to the on position and the alternator light is now on and goes off after ignition as it should. A little puzzling. I'll just have to keep an eye on this to see if the battery wil need recharging again. I will test the battery voltage with the car off and with it on idle.
__________________
Carl, |
||
|
05-15-2009, 01:22 PM
|
|
