1972 Ford F100 Alternator/Voltage Regulator wiring

1972MasterWiring_01.jpg (1592×1696) (fordification.com)

If the battery is no good,then you will hear the alternator
hum all the time, trying to charge it

Check for diode problems & A/C Ripple on the circuit

Check all vehicle grounds (wires)

If the wiring is good & the light comes on, it isn't charging
properly,have you not metered that,voltage,amperage &
ripple

You can go through 3 alternators from the auto part chains, to
find a good one.

The capacity of the alternator ( 35 amp or 100amp ) will make little difference to charging a battery. It has to do with the voltage regulator which may be internal in the alternator or external on the engine bay. The other fault that will not allow a battery to charge is the rectifier as if a diode has burnt out then the voltage that is being regulated is ac and it will not work anyway. The capacity of the alternator is determined by the total current draw when everything is switched on and should be around 10 amps more than what is required. IT not then the battery will slowly drain down because the alternator is not capable of running every thing and charge the battery as well. I suggest that an accredited auto electrician be engaged to sort this problem out

Sorry iam a thick brit having problems with your spelling which as we all know we cannot spell in the UK or pronounce aluminium or tomatoes so the man to ask is emmisionwiz as hes a ford dealer fitter with enough years under his belt to know exactly what you need to know ,so try a direct question ,but for this year with a seperate regulator why not try a alternator off a later model with a built in regulator ,as for the starter motor then a wire from the contact switch on the back of the key switch that has power when the key is turned to the start position and this wire goes to the small terminal on the starter motor .I do not the facility of a fancy pen thing attached to my computer that i can draw a quick pic for you .

Your alternator-mounted voltage regulator has failed. Luckily, your voltage regulator is
replaceable separately from the alternator (most voltage regulators are integral to the alternator,
and cannot be separately serviced).

Note: this works for 3.8L cobra alternators/voltage regulators only - in the 4.6L model, the
voltage regulator is an integral component of the alternator.

1999 Ford Mustang Cobra -3.8L engine

3.8L Engines

1. Disconnect the negative battery cable.

2. Remove 4 Torx® head screws holding the voltage regulator to the alternator rear housing. Remove the regulator, with the brush and terminal holder attached.

Fig. 1. The regulator and brush/terminal holder are mounted on the backside of the alternator




Fig. 2. The regulator and brush/terminal holder are secured by 4 Torx® head machine screws




Fig. 3. Hold the regulator while removing the screws to prevent the regulator from dropping out and damaging the brushes





3. Hold the regulator in one hand and pry off the cap covering the A terminal screw head with a small prybar.

4. Remove 2 Torx® head screws retaining the regulator to the brush holder. Separate the regulator from the brush holder.



Fig. 4. Slide the regulator out-the brushes will move out of the holder




Fig. 5. The brush and terminal holder can be separated from the regulator once it is removed from the alternator




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To install:

1. Install the brush holder on the regulator with 2 retaining screws. Tighten the screws to 25-35 inch lbs. (2.8-4.0 Nm).

2. Install the cap on the head of the A terminal screw.

3. Depress the brushes into the holder and hold the brushes in position by inserting a standard size paper clip, or equivalent tool, through both the location hole in the regulator and through the holes in the brushes.

Fig. 6. When installing the regulator, press the brushes back into the housing




Fig. 7. Use a thin piece of soft material, like this plastic wire tie, to hold the brushes in position while replacing the regulator, or use a paper clip inserted in the hole





4. Install the regulator/brush holder assembly and remove the paper clip. Install the attaching screws and tighten to 20-30 inch lbs. (2.3-3.4 Nm).

5. Connect the negative battery cable.

It should however you may need to use the mounting bracket from the 79 there bolth 302 ;s it should work

alternature to be replace

where did you buy the new alternator? Are you sure the alternator is good? Have the alternator tested before you spend time/money on your other components. If your wires are damaged or corroded, that's another problem.

turn your vehicle on, disconnect the battery, both terminals(while truck is still on) if it dies on you, then either the alternator is bad or wiring is wrong. if it stays on, then you may have a bad battery or voltage regulator. Check the voltage on the battery before you turn it on(should be from 11.5v-12v), when you turn it on if the alternator if working properly you should have around 13v-14v.

run a jumper from your alternator to your battery. This is a temporary fix and should stabilize the voltage and charge the system. It seems there is a short or grounding problem somewhere between the alternator and battery, so you will need follow the wiring but given the age of the vehicle, you should change the wiring from your generator or alternator to your battery. Be sure when you are running a jumper, your gauge wire is heavy enough and make sure the wire isn't hot. This is a temporary fix so don't go on a long road trip.