alternator wiring help

[dmiller]

i am using a ford alternator and voltage regulator.

the alternator has three insulated terminals: white one is labeled "fld"; red one is labeled "bat"; and the black one is labeled "sta".

The voltage regulator has four terminals: from left to right when facing the plug end, they are labeled: "I"; "A"; "S"; and "F".

i removed a ford alternator harness from the wrecking yard, and found only three of the voltage regulator terminals were wired.

please advise which wire goes where. and how large should the wires be. and since the voltage regulator is mounted to fiberglass, how large should the ground wire from the regulator to the chasis be? am i correct in thinking that the voltage regulator "dumps" excess current that the alternator makes to the chasis to control the voltage?


i thank you in advance.

doug

[dmiller]

i read the wiring instruction book, and they use a different voltage regulator, i'll order one from weaver monday. unless answers to earlier questions are forthcoming.

[nolastyankee]

Doug,
I am in the middle of a resto-build and just pulled the wiring harness out of my 289 yesterday. The car ran fine and didn't appear to have any electrical problems and from what I can tell was done right. I took some shots of the starter solenoid and voltage regulator before removing them which may be of help. The car is running a Ford alternator and regulator as well. As you indicated, the terminals are marked "I,A,S,F" from L to R. On my car the I terminal and the negative terminal of the starter solenoid were connected to an engine block ground; The A terminal was run to the positive side of the starter solenoid; The S terminal was run to the Stator (Sta) terminal of the alternator; The F terminal was run to the Field (Fld) terminal of the alternator. This matches my wiring diagram booklet.

Good Luck!
http://www.uniquecobra.com/uploaded/nolastyankee/Dscn7921.jpg

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[nolastyankee]

[8] Let me clarify my above post about the car being "done right"...The Spence car overall does not exhibit model workmanship, but the wiring appears to be have done by someone else and looks to follow the diagram. Despite looking awful, everything works.

:) The car is, however, being completely rebuilt for a very good reason...

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[dmiller]

NOLASTYANKEE:

thank you!

i have some idea how to proceed, now.

have a good holiday.

doug

[Okiesnake]

The small voltage regulator that Unique offers are nice in that they are small and mount to the alternator itself so that it works like a one wire alternator and you can still use a Ford alternator. See http://pages.sbcglobal.net/tdockstett/VRminFg.jpg . However, when mine failed, I recently replaced the alternator with a (don’t tell anyone) a GM one wire alternator with an internal voltage regulator.

[dmiller]

i'm still confused, my alternator has three insulated terminals. stator, field, and bat.

the one labeled bat. is the largest,

any ideas?

thanks

doug

[nolastyankee]

Doug,
Some of the wiring for the alternator needs to come from the harness. Specifically there should be a red wire from the harness which connects to the Bat (Battery) terminal of the alternator. In the picture I posted below, The larger white wire and smaller blue wire on the "S" and "F" tabs as descibed below run directly from the regulator to the alternator. The larger blue wire connected to the "A" tab runs through the red side of the starter solenoid and then appears run to the Battery terminal of the alternator.

Electrically this makes sense to me, but I replaced a '66 Mustang alternator and regulator earlier this year which was mechanically the same but was wired very different. You might want to verify all of this with Alan or the company who sources their harnesses. Good luck.

Unique 9122 - 289 FIA Cobra - The Legendary "Spence" Car

[dmiller]

i found a wiring diagram on club cobra, and it now makes sense.

thanks for the help. hope to finish wiring now.

doug

[Poorboy]

nolastyankee
Which terminal are you calling the ground on the starter solenoid??

Poorboy

[Okiesnake]

Doug, I just saw this post on CC http://www.clubcobra.com/forums/showthread.php?s=&postid=420935#post420935 Might be of help.

[dmiller]

okiesnake,

thank you.

wiring it tomorrow. got a good diagram from the cobraclub forum.