Team Chevelle banner
  • Hey everyone! Enter your ride HERE to be a part May's Ride of the Month Challenge!

1 - 5 of 5 Posts

·
Registered
Joined
·
723 Posts
Discussion Starter · #1 ·
This is for my 69 cutlass, which should be the same as a chevelle.
I installed a stereo this winter. I also cleaned up the engine compartment. This included removing the plug in wires to the external regulator, to run the wires in a different position. There were 4 tangs on the regulator. It seemed that one tang was pushed way out of position, almost like it was bent out of the way. In any event I straightened all tangs and inserted the wiring clip. Fit well. Never started the car until a few weeks later. Then I found that the battery kept getting weaker and weaker. Finally the red AMP light came on in the dash (I have idiot lites). I checked the voltage output at the battery, and it showed only 12 volts with the car running. I think this should be about 13 or 13.5.
So I think I have a generator or alternator problem. BUT HERE IS THE INTERESTING PART.
Someone before me installed a 55 amp alternator from a 79 camaro with internal regulator. It has the wire clip coming out the top of the body. My chassis service manual says I need a generator, 37 amp, with external regulator. (the 442 in 69 was apparently the only car with internal transistorized regulator, in the olds line).
MY QUESTIONS: Can you run an alternator with built in regulator in a car with an external regulator on the firewall? What do you do with the regulator? By pass it? Was the bent tang on the external regulator that I found an attempt to bypass the external regulator?
 

·
Registered
Joined
·
7,762 Posts
MY QUESTIONS:
"Can you run an alternator with built in regulator in a car with an external regulator on the firewall?"

It can stay there but it's no longer wired into the circuit. It hasn't any purpose.

"What do you do with the regulator? By pass it?"

Yes

"Was the bent tang on the external regulator that I found an attempt to bypass the external regulator?"

Could have been but not a good job. Read this.
http://www.chevelles.com/techref/ftecref14.html
 

·
Registered
Joined
·
723 Posts
Discussion Starter · #3 ·
I have now read Wes Vann's tech article. Thanks. I have found that Year One offers a wire harness accessory for this conversion. It plugs into the 4 wire harness plug at the external regulator. From the Year One photo, it joins the 2 outer wires (of the 4), which would be a jumper of the blue to brown wire. That is consistent with the Vann tech article.
However, the Year One harness shows they also jump or join the 2 inner wires of the 4. This would be a jumper or join of the white and orange wires. This is not part of Vann's article. He shows each capped off.
Now as part of this Year One conversion kit, they have a harness for the alternator end, to deal with the different plastic plug-in connectors for the ext. regulated and int. regulated alternators. But Year One is connecting the white wire of the original harness to the #2 terminal as best I can tell.
SO, from looking at the YO conversion kit, would it be correct to also join the white and orange wires at the firewall ext. regulator connector and then connect the white wire at the alternator to the #2 terminal? (we all agree blue goes to #1 at alternator). This would avoid the need to jump from the BAT terminal on the alternator to the #2 terminal as prescribed by the Vann article. Has anyone done this?
I would like to avoid having the white wire capped and hang without being connected to anything at the alternator. The above Year One setup seems to avoid this.
My last Q.---- Does the #2 terminal on the int. regulated alternator need 12 volts at all times (unswitched so to speak) Or can it be switched power after the key is on?
 

·
Premium Member
Joined
·
2,223 Posts
If I understand it correctly, the #2 terminal is a sense terminal. In Wes Vann’s instructions it is connected to the alternator output. In this case the regulator will adjust the field to maintain regulated voltage at the alternator output. In the case of the YO kit the #2 terminal is sensually connected to the horn relay, the regulator will maintain set voltage at the horn relay rather than the alternator output. Something to consider, GM used a #12 wire for the #2 connection. I’m guessing it is to reduce the chances of a voltage drop across the sense wire between the reference point and the #2 terminal. Will it make a difference using a #14, the factory installed white wire? I don’t know.

To answer your last question. Either Wes Vann’s way or YO’s will work. However leave it hot all the time, I wouldn’t switch it.
 

·
Registered
Joined
·
723 Posts
Discussion Starter · #5 ·
Thanks for the advice. I think I now understand the wiring basics. I just tested the red (orange on Vann's article) wire at the external regulator connector, it is hot all the time. So by joining red to white there, you get the white wire at the alternator hot all the time, which is what we want. This confirms the YO setup should work and accomplish the same purpose as Wes V's setup.
However, I am now confused as to whether I have an internally regulated alternator. It is # 1102479 55 amp, date coded 9D 5. My chevy id numbers books lists this as correct for 79 Nova, or Camaro. The case is stamped #1 and #2 for the plug in wires, not R and F like the old style.
However, every SI alternator I have seen has these two prongs in the alternator running - -.
MINE GO UP AND DOWN, like this ||. Hence the old wire harness will plug right into the socket, but the white wire was plugged into the #2 terminal, and the blue into the #1. This is opposite the Vann article and all others I have read.
Q-- Is my alternator a SI internal regulated?
Q-- is this setup for wires to the #1 and #2 terminals stock and correct, or did someone go into the alternator and modify the terminals so it would take the old style wire harness plug in?
Q-- is everyone sure that the white wire (hot all the time) go to the #2 terminal, and the blue wire (going to the GEN lite in dash) goes to #1?
 
1 - 5 of 5 Posts
Top