smrz914
Jun 5 2005, 09:49 PM
So I finally did something on my 914 v8. I couldn't stand not doing at least something on my car. There have been to many progress threads and then meeting club people at Parts Heaven today I had to get my fix (even if I didn't get enough of the fix). I want to do more work. I hooked up the idiot light. The alternator is a AC Delco 7127 that is internally regulated, 3-wire alternator.
wires:
1. Ground
2. Positive battery
3. Idiot light (#1 terminal on alternator)
4. #2 trerminal wire on alternator just goes to the positive post on the alternator. (not counted as a wire)
For my 72 the idiot light wire is green/red. If you still have the relay board then the green/red wire goes to the number 5 spot (according to Haynes) and leaves the relay board as a green/red wire. I don't have a relay board so I just extened the green/red wire to the alternator. Maybe this can help someone with their v8.
914GT
Jun 5 2005, 10:03 PM
Perfect timing Paul. I just got my engine back in the car today and tomorrow will finish up the installation. I had labeled the two wires for my alternator light and volt. sense, but didn't remember which terminal they went to.
smrz914
Jun 5 2005, 10:30 PM
Awesome. It pays off to post stuff you have done, even if it's a little thing. Glad I could help somone on the board. So now I need to figure out some other projects that I can do without a garage.
smrz914
Jun 5 2005, 10:54 PM
Is there a way to test to see if the idiot light is working? A test to see if the light will light when there is a problem with the alternator? I figure it's a good thing to check. Should I just disconnect the connector on the alternator? Thanks
914GT
Jun 10 2005, 08:50 AM
QUOTE (smrz914 @ Jun 5 2005, 08:49 PM) |
4. #2 trerminal wire on alternator just goes to the positive post on the alternator. (not counted as a wire). |
This is the usual way to wire it but I connect a wire from terminal 2 to a junction terminal next to my battery. This regulates the voltage a little higher by cancelling out the voltage drops in the wiring.
lapuwali
Jun 10 2005, 09:10 AM
I've never used a GM regulator, but that wiring diagram looks bizarre to me. The Bosch, Lucas, and Japanese internally regulated alternators all have a much simpler setup, where there's only the one fat wire to the + terminal on the battery, and one thin lead to the lamp, with the other terminal on the lamp going to switched +12. 100% of the field current then flows through the lamp until the alternator is self-energizing, when the lamp goes out as the voltage will now be equal on both sides.
Why the second thin lead from the regulator to unswitched +12? Why the bypass wire around the lamp?
914GT
Jun 10 2005, 09:27 AM
Looking at the source of Paul's image it's off a Buick restoration website, so it's not exactly the same as the 914's wiring at the alternator light. The #2 terminal is a high-impedance sense input for the regulator. You can connect it right at the output and it will regulate at that point. If you connect it to a point closer to the load it will regulate the voltage from that remote point in the system, and the alternator will put out a higher voltage. I wired mine this way so I could get a little higher voltage at my electric water pump.
914GT
Jun 10 2005, 09:29 AM
QUOTE (smrz914 @ Jun 5 2005, 09:54 PM) |
Is there a way to test to see if the idiot light is working? |
Just disconnect the wire from the alternator and touch it to ground, the light should come on with the ignition on.
Dave_Darling
Jun 10 2005, 11:34 AM
QUOTE (smrz914 @ Jun 5 2005, 07:49 PM) |
For my 72 the idiot light wire is green/red. If you still have the relay board then the green/red wire goes to the number 5 spot (according to Haynes) and leaves the relay board as a green/red wire. |
Wrong idiot light wire. That's for the oil pressure warning light.
On a 914, the light to the alternator warning light is blue.
--DD
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please
click here.