Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> 914 alternator light on when I step on brake, Advice please
recko911
post Dec 6 2010, 03:31 PM
Post #1


Member
**

Group: Members
Posts: 93
Joined: 6-February 06
From: Los Angeles, CA
Member No.: 5,535



I have been having issues with my starter. I doesnt start as usually as if it struggles. I check battery voltage with car off and it's around 12.35 with car running at 12.80 volts and with all lights on and car running it goes down to 12.40 volts. I also notice when I am driving and I step on brake the alternator light dims on. Has anybody had this problem.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
McMark
post Dec 6 2010, 03:32 PM
Post #2


914 Freak!
***************

Group: Retired Admin
Posts: 20,179
Joined: 13-March 03
From: Grand Rapids, MI
Member No.: 419
Region Association: None



With the car running and all the lights off, you should be getting closer to 13.8 (measured at the battery).
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
recko911
post Dec 6 2010, 03:46 PM
Post #3


Member
**

Group: Members
Posts: 93
Joined: 6-February 06
From: Los Angeles, CA
Member No.: 5,535



QUOTE(McMark @ Dec 6 2010, 01:32 PM) *

With the car running and all the lights off, you should be getting closer to 13.8 (measured at the battery).


When I turn on vehicle it doesn't start quickly it cranks slowly then turns on. I can't explain the alternator light turning on when I step on brake
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Dec 6 2010, 04:23 PM
Post #4


Custom Member
***************

Group: Members
Posts: 24,584
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



Check your ground strap from the battery to the body, clean it
Check your ground strap from the transmission to the body, clean it.

Take both off and use a wire brush or a dremel with a wire brush to get down to bare metal.
I replaced the transmission ground strap with a new one from the FLAPS store...the older braided straps tend to not work well after 40 years.

that may explain why you are having a hard time starting and you are drawing to much current.

The low charging issue (you should have 12.7 -13.7 volts when charging)
could be more dirty connections (clean both at the battery, clean all of them at the starter also.

chase the wire from the alternator to the relay board and clean that one with electrical contact cleaner and a tooth brush.

These old german cars are well known for needing some cleaning of the grounds and plugs after 40 years on earth. Any car needs this.

RIch
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
McMark
post Dec 6 2010, 04:53 PM
Post #5


914 Freak!
***************

Group: Retired Admin
Posts: 20,179
Joined: 13-March 03
From: Grand Rapids, MI
Member No.: 419
Region Association: None



(IMG:style_emoticons/default/agree.gif) Cleaning connections is a GREAT maintenance task on these cars. Often neglected, and usually quite helpful.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
recko911
post Dec 6 2010, 07:30 PM
Post #6


Member
**

Group: Members
Posts: 93
Joined: 6-February 06
From: Los Angeles, CA
Member No.: 5,535



Just checked voltage 12.5 volts car off, running 14 volts. Running with lights on. 13.5 volts. I also noticed that the alternator light is on I removed the gauge and noticed the bulb was dim very low and when I step on the brake it lights up further.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Dec 6 2010, 08:13 PM
Post #7


Custom Member
***************

Group: Members
Posts: 24,584
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



remove and clean your fuses...they may look good, but they may have enough crud in there to cause a problem

Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Spoke
post Dec 6 2010, 08:39 PM
Post #8


Jerry
*****

Group: Members
Posts: 6,986
Joined: 29-October 04
From: Allentown, PA
Member No.: 3,031
Region Association: None



QUOTE(recko911 @ Dec 6 2010, 08:30 PM) *

Just checked voltage 12.5 volts car off, running 14 volts. Running with lights on. 13.5 volts. I also noticed that the alternator light is on I removed the gauge and noticed the bulb was dim very low and when I step on the brake it lights up further.


The bulb voltage is the difference between the battery voltage and the voltage at the voltage regulator. Remove the gauge and measure each terminal of the bulb to ground. Sounds like you have connections that have oxidized and are acting resistive.

Clean your grounds and maybe even your battery terminals.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 28th May 2024 - 05:58 PM