Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Dec 2002
Location: Boulder Colorado
Posts: 3,704
Garage
Generator Problem...but I just read 6 pages of generator light threads...

And it seemed like half of them were 74 CIS cars. My 74 became harder and harder to start, then started running rough and wouldn't start. I thought the coil was bad and swapped it. I thought the CDI was bad and swapped it. I finally reset my points and it runs fine...but the generator light is on. I check voltage across the battery terminals at 2000 rpm and showed 12.56 volts. I figured I would check the alternator...local shop said it was bad and swapped me out for a rebuilt exact replacement. Installed it today, car started right up, but generator light was still on. I checked voltage across the battery terminals...you guessed it 12.56 volts at 2000 rpm. Could something have happened when I was swapping the CDI and coils around? When I regapped the points...could something have gone awry? I have followed my wiring diagrams and everything is hooked up correctly and ground straps are in place. I checked the back of the instrument and the wires don't seem compromised. Something seems fishy...I know when the VR dies, the voltage acroos the battery terminals goes up. Is it possible for the VR to die and not have the voltage go up? Belts are tight...hmm

Thanks

Speedo

Old 08-22-2009, 08:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
ischmitz's Avatar
 
Join Date: May 2002
Location: Santa Barbara, CA
Posts: 4,810
Garage
Send a message via Skype™ to ischmitz
If your wiring is fine the next guess would be the VR. I don't think there is only one way a VR can fail. If the VR passes D+ straight to DF that would cause the alternator to overcharge. If the D+ terminal is internally disconnected inside the VR you would see what you describe: The light never goes out and the alternator doesn't charge. I would get a new VR.

Ingo
__________________
1974 Targa 3.6, 2001 C4 (sold), 2019 GT3RS, 2000 ML430

I repair/rebuild Bosch CDI Boxes and Porsche Motronic DMEs
Porsche "Hammer" or Porsche PST2, PIWIS III - I can help!!
How about a NoBadDays DualChip for 964 or '95 993
Old 08-22-2009, 09:28 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Dec 2002
Location: Boulder Colorado
Posts: 3,704
Garage
Ingo...you were right

I had an archaic Marchelle VR. I deleted all the old noise supression crap, installed an updated VR and the problem went away. I start the car and the generator light comes on...as soon as I apply throttle...2000 + rpm it goes out. Weird thing...I opened up the Marchelle VR and it all looked ok...nothing burnt.

Thanks again...

Speedo

Old 08-23-2009, 06:07 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Reply


 


All times are GMT -8. The time now is 12:52 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.