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I was looking over a wiring schematic for my 1984 f150, and noticed that my alternator wiring didn't line up with what was described. I have the orange and light blue wire as well as the black and orange for the F and B terminals. but no white and black white of the S terminal. Instead that has an aftermarket wire running to the started solenoid on the same side as the wire that runs down to the starter.
I found a yellow and blue wire that was cut off in the loom but it appears to follow the harness into the cab so I'm not sure if it's relevant. I don't know how but the alternator did work when i had a motor in here so this might be best left unsolved
Upon completely exhuming the wires i found this. It appears that the BAT wire is magically connected to these other 2 one heads the battery side of the solenoid the yellow goes to a connector then into the cabin still no white wire in sight
I think i managed to solve this mostly on my own I'm gonna have to get some solder and heat shrink to fix the connection for the heavy gauge wires and it appears that the S terminal was only for the electric choke. Apparently this truck didn't originally do it that way. Sometimes i hate working on stuff after other people
Ok that wire on the same side as the cable going to the starter needs to come off both ends.
Nothing goes on the starter cable side!
Does your truck have gauges or lights? It makes a difference on how the ALT get wired.
Some trucks, think v8 with gauges, did not have anything on the "S" stud of the ALT
The trucks with gauges and the 300 six had the W/B wire on the "S" stud that went to the hot air asst. choke cap like my truck.
Think trucks with lights that "S" stud wire went to the regulator but lets see what others have to say.
That O/B wire is about right.It goes to the battery to charge it and the yellow wire is the power feed into the cab and it picks it up in the harness.
Got to love the factory splices
Dave ----
I think i managed to solve this mostly on my own I'm gonna have to get some solder and heat shrink to fix the connection for the heavy gauge wires and it appears that the S terminal was only for the electric choke. Apparently this truck didn't originally do it that way. Sometimes i hate working on stuff after other people
You are correct, some installations did not have a wire hooked to the "S" terminal on the alternator from the factory.
Ok that wire on the same side as the cable going to the starter needs to come off both ends.
Nothing goes on the starter cable side!
Does your truck have gauges or lights? It makes a difference on how the ALT get wired.
Some trucks, think v8 with gauges, did not have anything on the "S" stud of the ALT
The trucks with gauges and the 300 six had the W/B wire on the "S" stud that went to the hot air asst. choke cap like my truck.
Think trucks with lights that "S" stud wire went to the regulator but lets see what others have to say.
That O/B wire is about right.It goes to the battery to charge it and the yellow wire is the power feed into the cab and it picks it up in the harness.
Got to love the factory splices
Dave ----
You are correct, some installations did not have a wire hooked to the "S" terminal on the alternator from the factory.
Alright my understanding is that it went to the electric choke on the straight 6s could i use that for an electric choke for my Edelbrock? The factory setup just took power from the coil feed but that's only 9 volts if i understabd how duraspark works
Alright my understanding is that it went to the electric choke on the straight 6s could i use that for an electric choke for my Edelbrock? The factory setup just took power from the coil feed but that's only 9 volts if i understabd how duraspark works
You DO NOT want to pull power from the coil + side as it can also pull power from the IGN and as you found is not a full 12 volts that some chokes need.
The good thing about using the S lug is it only supplies power when the motor is running. Any other power supply may be hot with the key on motor off.
Now you can try and use the S lug from the ALT to the choke and see if it works because it is also about 6 to 8 volts.
It may not open the choke fast enough but the only way to know is to try it. You may get it to work good with adjusting the choke to use the ALT wire.
The other thing you can do if you find the S lug dose not work right is to use it to trigger a relay that supplies 12 volts to the choke.
Dave ----
You DO NOT want to pull power from the coil + side as it can also pull power from the IGN and as you found is not a full 12 volts that some chokes need.
The good thing about using the S lug is it only supplies power when the motor is running. Any other power supply may be hot with the key on motor off.
Now you can try and use the S lug from the ALT to the choke and see if it works because it is also about 6 to 8 volts.
It may not open the choke fast enough but the only way to know is to try it. You may get it to work good with adjusting the choke to use the ALT wire.
The other thing you can do if you find the S lug dose not work right is to use it to trigger a relay that supplies 12 volts to the choke.
Dave ----
Alright probably gonna go with the relay idea. And at this rate keep hunting down all of the f**ked wiring in this truck
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