73 with tach, alternator wiring question

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71steed

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66 GT coupe
67 GTA convertible
69 Fastback, Boss 429 clone
69 GT coupe
71 Sports coupe
71 Mach 1
73 Mach 1
If anyone has a 73 with a tach and gauges, maybe you could help me.  There are two yellow wires coming out of the regulator plug.  One is for the radio resistor.  The other one has an eyelet terminal on the end.  The schematic says it goes to the junction block, the one that connects the two thick black/orange stripe wires.  I have doubts that the yellow goes there.  If you have a 73 with tach, peak under the hood and see where that yellow wire connects to.  Thanks in advance.

 
Steed,

I checked and the other yellow wire goes to the positive battery cable side of the starter solenoid.

Thanks, Jay
Or the junction block.  Ford, jeez.   Thanks.

 
pictures of stock regulator, solenoid, and terminal block on a car with tach, gauges, and the accessory wire for hood light, convertible roof pump, and power windows.





 
pictures of stock regulator, solenoid, and terminal block on a car with tach, gauges, and the accessory wire for hood light, convertible roof pump, and power windows.





Can you identify the connections to the voltage regulator in terms of which wire goes to what terminal (FSAI)?

I'm struggling to understand the wiring diagram. Mine is a 1972 with stock tachometer and ammeter. 

What I've understood so far is the

F >> O-LB wire to alternator

S >> Connected to LG-R wire

A >> Unsure??

I >> Unsure??

Thanks for your help!

Marco
 
The F terminal wire goes to the field terminal on the alternator, and is orange/light blue stripe.

The A terminal wire is yellow with white dots and has two connections. One is to the battery terminal and/or black/orange stripe wire at the alternator or terminal block. The other one goes to the radio noise suppressor.

The I and S terminals depend on whether or not you have a factory ammeter.

WITH a factory ammeter the I terminal is not used.

WITH a factory ammeter the S terminal red/light green stripe wire is connected to the ignition switch.

WITHOUT a factory ammeter the I terminal wire is red/light green stripe that is connected to the alternator warning (idiot) light and then the ignition switch.

WITHOUT a factory ammeter the S terminal wire is white/black stripe and is connected to the stator terminal on the alternator.

 
F >> O-LB wire to the alternator

S >> Connected to LG-R wire

A >> Two Yellow-W Dot wires with one going to a noise suppressor and the other to the battery side of the starter relay or a terminal block.

I >> Not used with gauges (LG-R only used with Alt Warning Lamp)

 
OK, Makes sense! 

I would also have essentially a two wire connection at the alternator (O-LB and the thicker "hot" wire going either to junction block or on the side of starter solenoid).

 I was also wondering where the white-black wire coming from alternator goes (on my loom it spits in a "y" ). On the wiring diagram they dismiss that circuit, (circuit 4),  if you have an ammeter. I was unsure and didn't want to start guessing and starting a car fire. XD

Thank you both Don and Rackerm for your informations!

Marco

 
The F terminal wire goes to the field terminal on the alternator, and is orange/light blue stripe.

The A terminal wire is yellow with white dots and has two connections. One is to the battery terminal and/or black/orange stripe wire at the alternator or terminal block. The other one goes to the radio noise suppressor.

The I and S terminals depend on whether or not you have a factory ammeter.

WITH a factory ammeter the I terminal is not used.

WITH a factory ammeter the S terminal red/light green stripe wire is connected to the ignition switch.

WITHOUT a factory ammeter the I terminal wire is red/light green stripe that is connected to the alternator warning (idiot) light and then the ignition switch.

WITHOUT a factory ammeter the S terminal wire is white/black stripe and is connected to the stator terminal on the alternator.
I have a Doppelganger!  Thank You, Midlife C! ;) :p

 
Thanks for the compliment, but your wiring guru title is not in jeopardy. While I know a lot about some automotive electrical things, and general automotive electrical/electronics and I'm good at reading circuit diagrams, I don't know a lot of the specifics. Like, if you ask me what's in a headlight harness, I'd say "Duh, wires to the headlights". I actually know there are more than that in that harness, but not everything. That is why you never see me respond to harness questions, and similar things.

 
Last edited by a moderator:
OK, Makes sense! 

I would also have essentially a two wire connection at the alternator (O-LB and the thicker "hot" wire going either to junction block or on the side of starter solenoid).

 I was also wondering where the white-black wire coming from alternator goes (on my loom it spits in a "y" ). On the wiring diagram they dismiss that circuit, (circuit 4),  if you have an ammeter. I was unsure and didn't want to start guessing and starting a car fire. XD

Thank you both Don and Rackerm for your informations!

Marco
 
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