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- Jul 14, 2023
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- Germany
- My Car
- Mustang Mach 1 Fastback 1973
Good to know, then I will also restore this factory state and not work with the 55 amp alternator. The yellow cable for the defroster is next to the black cable as you described. It is currently not connected and has been literally "shredded". I have to repair that first. I can't say what else the previous owner left wrong or incorrect. I have spent hours reading through documents and manuals but I am not a mechanic and do this as a hobby. Thanks for your great help, thanks Doug!70 amp alternators are correct for 73 Mach 1s that have factory rear defrost. I believe 55 or 61 amp without the rear defrost. Connections to the 70 amp alternator are different than for the lower amp alternators. 73 was the only year to use the 70 amp alt. This was do to the 73 rear defrost being higher wattage (higher amp draw) than 71/72s. 73s used a dedicated rear defrost 12 volt feed (yellow with integral fusible link) connected to the junction block forward of the starter solenoid if the car was equipped with factory amp meter according to the 73 Mustang wiring diagram. To the starter solenoid battery post without amp meter. 71/72s used a black yellow hash feed wire connected to a circuit breaker at the solenoid, that feed wire also used for to feed the convenience group, power windows or convertible top. 73s also used a black yellow dash feed wire for the convenience group, PW or convertible top only, not for the rear defrost feed.
PS: is the integral fusible link is still available because at my yellow cable is nothing any more, as i said, shredded.70 amp alternators are correct for 73 Mach 1s that have factory rear defrost. I believe 55 or 61 amp without the rear defrost. Connections to the 70 amp alternator are different than for the lower amp alternators. 73 was the only year to use the 70 amp alt. This was do to the 73 rear defrost being higher wattage (higher amp draw) than 71/72s. 73s used a dedicated rear defrost 12 volt feed (yellow with integral fusible link) connected to the junction block forward of the starter solenoid if the car was equipped with factory amp meter according to the 73 Mustang wiring diagram. To the starter solenoid battery post without amp meter. 71/72s used a black yellow hash feed wire connected to a circuit breaker at the solenoid, that feed wire also used for to feed the convenience group, power windows or convertible top. 73s also used a black yellow dash feed wire for the convenience group, PW or convertible top only, not for the rear defrost feed.
The thick yellow wire with the fusible link 14a is #37 on the diagram and goes over the engine along with the black and yellow wire for the power windows etc, attached to the stabilizers for the dome struts. the other yellow wire 37 is part of the main harness and goes under the fan and then attaches to the terminal block. did i summarize this correctly so far, not that i'm mixing up the wires. bzzzzz--boom![]()
The fusible link is ordered and will be delivered in the middle of july to germany.You'll have to get a repair end for the fusible link. Some yellow shrink tubing will hide it from the casual observer.
https://www.rockauto.com/en/tools/electrical,fuse,fusible+link,1000927
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