1974 Alternator / regulator
06-17-2004, 05:42 PM
#1
Track Day
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1974 Alternator / regulator
Hello all,
Do the 1974 model alternators have built in regulators? Does anyone have a wiring diagram for the wires leading up to the alternator? Most books just say, "Label the wires so you do not hook them up incorrectly."
My alternator light is on and I am going to start troubleshooting it this weekend. It's a new rebuild and I just got the engine in a couple of weeks ago so it's probably something simple.
Thanks for the help,
Stephen
Do the 1974 model alternators have built in regulators? Does anyone have a wiring diagram for the wires leading up to the alternator? Most books just say, "Label the wires so you do not hook them up incorrectly."
My alternator light is on and I am going to start troubleshooting it this weekend. It's a new rebuild and I just got the engine in a couple of weeks ago so it's probably something simple.
Thanks for the help,
Stephen
06-18-2004, 01:17 AM
#2
RL Technical Advisor
Stephen:
74's have separate VR's located on the left side of the engine compartment. Its the silver slightly rectangular shaped relay on the panel.
VR connections are:
1) Blue wire to D+
2) Black wire to Df (field)
3) Brown wire(s) to D-
Enjoy!
74's have separate VR's located on the left side of the engine compartment. Its the silver slightly rectangular shaped relay on the panel.
VR connections are:
1) Blue wire to D+
2) Black wire to Df (field)
3) Brown wire(s) to D-
Enjoy!
07-12-2004, 11:55 AM
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Track Day
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Thanks for the info!
I Finally got time to pull the alternator and it has a new alternator with a built in regulator. I took it to a local shop and it works fine. I pulled the gauge cluster out where the lamp resides. I do not see any type of resistor behind the lamp. I read the Technical Bulletin that states that there should be a resistor 911 641 981 00 with connector 111971511 placed behind the lamp. And, that the lamp should be switched out from 2 watts to 4 watts. Has anyone does this before? Should I be able to see this resistor directly behind the lamp or is it possible the previous owner placed it inline at a different location? Also, does anyone know the specs for the resistor? The porsche dealer said it would take 2 weeks to get the part and would not provide specs on the part. What type of voltage should I be getting on the blue wire that connects to the alternator for the regulator to work properly?
Sorry for all the questions, this has been frustrating....
-Stephen
I Finally got time to pull the alternator and it has a new alternator with a built in regulator. I took it to a local shop and it works fine. I pulled the gauge cluster out where the lamp resides. I do not see any type of resistor behind the lamp. I read the Technical Bulletin that states that there should be a resistor 911 641 981 00 with connector 111971511 placed behind the lamp. And, that the lamp should be switched out from 2 watts to 4 watts. Has anyone does this before? Should I be able to see this resistor directly behind the lamp or is it possible the previous owner placed it inline at a different location? Also, does anyone know the specs for the resistor? The porsche dealer said it would take 2 weeks to get the part and would not provide specs on the part. What type of voltage should I be getting on the blue wire that connects to the alternator for the regulator to work properly?
Sorry for all the questions, this has been frustrating....
-Stephen
Last edited by porsche_911_s; 07-12-2004 at 11:12 PM.
07-13-2004, 12:35 PM
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Stephen:
That's a 91 ohm 5 watt resistor. Just solder it across the two terminals of the lamp. The lamp does not have to be changed, That's why you're adding the resistor. good luck
That's a 91 ohm 5 watt resistor. Just solder it across the two terminals of the lamp. The lamp does not have to be changed, That's why you're adding the resistor. good luck
