Team Camaro Tech banner

1 - 17 of 17 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter #1
The car is a 69' with a 396. The alternator and regulator appear to be wired as stock. My alternator has the heavy red wire off one post, a black wire off the other post going to the neg battery terminal and the blue and white wire from the plug off the back. The white wire has been disconnected from the alternator and the VR. The VR appears to be the original style. My question is why would the white wire be disconnected on both ends, what is its function? The car is being charged.
 

·
Super Moderator
Joined
·
32,282 Posts
The red wire is the power supply, BATT, and is used to supply power for the electrical system and recharge the battery when alt is running.
Black wire is probably connected to an alt case non-insulated stud and goes to neg post to place the alt case and battery on the same ground plane/reference level.
Blue wire is field supply telling alt to charge.
White wire is field return for energizing field relay turning off the GEN light in instrument cluster as ign voltage is supplied to the other side of GEN light.

Does GEN come on with ign key on, engine off?
Why it would be disconnected, I don't know, unless GEN bulb is burned out or the car has console gauges then GEN was chosen not used by previous owner(s).
 

·
Registered
Joined
·
56 Posts
Discussion Starter #4
unless GEN bulb is burned out or the car has console gauges then GEN was chosen not used by previous owner(s).
Why would a burnt out GEN bulb justify disconnecting the white wire and what effect would that have on the charging system? The car does not have console gauges.
 

·
Super Moderator
Joined
·
32,282 Posts
GM designed a parallel path from the ign sw to VR around the GEN bulb so in case the bulb did burn out, the charging system still works.
The parallel paths are: 1. wire from ign sw to bulb to VR; 2. Brown/white of smaller gauge wire from ign sw to VR, actually both go to firewall connection, then single wire to VR.
Why the disconnected white wires, I have not a clue.
 

·
Super Moderator
Joined
·
32,282 Posts
You have three to chose from:
10SI
12SI
CS130 series, maybe four choices,
CS144 series - powers your house........

The 10 &12 are the same install, 10SI puts out 20 amps less than a 12SI, both both hook up the same in the conversion:
On the VR connector, jumper the two inside terminals together and jumper the two outside terminals. AT the alt connector, blue wire to '1' terminal and white to '2' terminal - just the reverse of the external reg'd alt connector in your hand.

CS Series is mount and wire the brown wire in car harness to 'L' terminal of alt connector to extinguish the GEN light after you replace it.

Of course, with all alts, red wire to BATT stud. If all heavy electronics is added in the car and power is from positve battery clamp, you mshould run a new min 8 AWG wire from alt BATT stud to battery pos post.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #8
Thanks for the help. One last question, currently my white wire is disconnected at both ends, isn't this wire needed to be in place for the alternator to charge?
 

·
Super Moderator
Joined
·
32,282 Posts
Apparently, not necessary in your application.
It's only use is to energize the field relay in the VR thus sending battery voltage to the other side of the GEN light once the alt is running to turn off the light.
For something to do, hook up the white wire and tell us what happens.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #10
In reading through the forums for converting to a 10SI or 12SI, I have found that those alternators need the resistance from the GEN light to activate the alternator. Is that correct or am I misreading it? Apparently my stock set-up does not need the GEN light.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #11
Made some progress. Reconnected the wire at the alternator and regulator. Turned key on but no GEN light. Started engine and noticed the regulator buzzing at low rpm. Increased rpm's and buzzing stopped. Took a closer look and noticed GEN bulb not installed. Put new bulb in and it would light while the reg was buzzing. Replaced reg with new one and the buzzing is gone and the light works as it should but voltage seems a little low at around 13 volts while running. The bulb socket is a mess. Someone obviously had problems with it in the past. The brown wire to the GEN socket was spliced with a wire nut. How hard is it to change that entire light cluster. Ther are alot of wires going to it.
 

·
Super Moderator
Joined
·
32,282 Posts
The inst cluster itself is not too bad, speedo cable, and connector plugged into the back.
Four screws on the interior side and a short ground strap at the top. Be sure to reconnect ground strap upon installation as without it, strange things happen.

As I suggested, there is a wire from ign sw to one side of GEN light and a brown/white small gauge wire, approx 10 ohms, to the firewall connector.
The other side of GEN is a single brown wire to the same firewall terminal.

Having a 13 volt recharge may show a low charged battery, might add an external charge on it for an afternoon and see what happens later.

Yes, internal reg'd alts need an excite voltage, usually from the ign sw.
Sense wire would be typically the horn relay buss bar or, the BAT spade on the fuse panel.
 

·
Premium Member
Joined
·
5,291 Posts
Are the terminals on your exsisting alternator like this l l or like this - -?
If they are up and down it's externally regulated. if across it's internal. I really wonder if it's not internal regulated one wire alternator already.

Jeff
 

·
Registered
Joined
·
56 Posts
Discussion Starter #14
It's definetely externally regulated. I am in the process of changing over to internal. The hard part is going to be fixing the hack job that was done to the generator lamp socket.

Thanks for all the help!
 

·
Admin/Super Moderator
Joined
·
12,511 Posts
Well the GEN light socket and harness are available if you want to drop in OEM style.

Everett am I right to assume that the white wire was the signal to the VR to stop charging? If so I would suspect they had some voltage issues, and the fix was to have the alternator field live all the time - always producing power, with the white wire disconnected, the GEN light was disabled to override the GEN light telling you there was a overcharging problem. But maybe I'm wrong it is after all Friday the 13th.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #16
Mission Accomplished! Light socket repaired, replaced all bulbs in idiot lights, installed new internally regulated alternator...all is good.

Thanks again for all the help.

Joe
 

·
Super Moderator
Joined
·
32,282 Posts
Cool! The white wire from the alt connects to the VR #2 and energizes the field relay placing battery voltage on the pink wire, VR #4, going back to the GEN light to turn 'off' the GEN light.
The PO may have done what you suggest. Only the Shadow knows..........
 
1 - 17 of 17 Posts
Top