Alternator Not Working Please Help 19 years old Need Help!!

[m-mman]

With the engine running, pull a battery cable. If the charging system is working at all the engine will stay running.[/quote
Back in the days with generators this was standard practice.
This is not recommended with alternators ,it can cause damage.

I have heard this for years and I have also been pulling cables for years to quickly test for charging capability.
I have found SOME Japanese cars that required a battery in the circuit in order for the charging system to function but never and old American car.

Yes the battery will act as a 'load' and would absorb peaks in charging voltage based on engine speed, belt slipage etc. But since the system is self energizing could somebody explain exactly what 'damage' might occur? and Why?

I understand that problems might arise to when trying to drive and add various loads to a charging system without a battery (Amp flow might exceed outout and voltage would drop to zero) but again what DAMAGE might happen?
The only thing I can imagine would be is an overwork situation and cause the output leads to get hot.

[70_F100]

Which instrument cluster do you have?

I may have an extra alternator wiring harness. I may even have one that's NOS.

[fordman]

the wiring on your regulator plug. is that suppose to have all 4 wires? do you have gauges in your dash or dummy lights?

as far as damage to the system. i dont knwo that is what i was tryign to find out. they say you should mess with the newer stuff or even jump a battery in a new car because it could burn out the diodes in the alt. do our alts have diodes in them?

[70_F100]

the wiring on your regulator plug. is that suppose to have all 4 wires? do you have gauges in your dash or dummy lights?

as far as damage to the system. i dont knwo that is what i was tryign to find out. they say you should mess with the newer stuff or even jump a battery in a new car because it could burn out the diodes in the alt. do our alts have diodes in them?

Fordman, all alternators that I know of have diodes in them.

An alternator generates AC voltage. The diodes allow current through them in only one direction, thus changing the output to DC voltage.

The only way I know of that diodes would be harmed by jump-starting is for the jumper cables to be hooked up backwards. Otherwise, jumper cables would, theoretically, work the same as a battery charger. It's nothing but a parallel connection, which increases "available" voltage and amps.

Alternately, hooking them up in series (vs. parallel) causes the voltage to add. That's how they are able to use multiple 6V batteries to create a 12V or 24V system, or multiple 12V batteries to power a 24V system.

Parallel circuit: Positive to positive, negative to negative, any positive and any negative may be used to provide power (voltage is the same throughout the circuit).

Series circuit: Positive to negative (any number of times) with the vacant positive and negative (at the end of the battery group/circuit) used for power. Voltage adds with each battery added to the circuit.

Different components in the different types of circuits (resistors, etc) react differently.

[72Highboy]

I have the instrament pannel that has the idiot lights "70-F100".

{QUESTION} Could hooking up the alternator wrong have fried something somewhere else when I took the alternator off the very first time when I bought it the previous owner had: sta, grd, fld, and bat hook up all wrong. I then corrected it but i am not sure if I relized that before I replaced the voltage regulator or after.

I have check the with volt with a meters like you get from radio shack and lowes, power is good to the battery but the alternator isn't wakeing up or engageing to send out the proper volts to keep the battery fully charged the 13 or 14 volts.

Tomarra I will take it down to autozone and check it.

{QUESTION} Because the alternator and voltage regulator are hooked up probably in some sequence, if the voltage regulator is fried will that prevent the alternator from properly working.

Thanks again guys.

[70_F100]

I'm assuming that you have a '72 with an FE, correct?

[fordman]

a bad regulator will keep the alt from working i have read.

[72Highboy]

Yes its a FE engine "70-F100" and when I pull the cable its only for a second or less because it will die right off the bat and I have tried pulling both.

[fordman]

the alt is bad or the wiring is wrong 1 of the 2.

[Banjo]

Ok, yes, if you plled postive cable and it died, alt is bad, in my opinion.

[70_F100]

For future reference, always pull the negative cable first. That applies whether you are taking your battery cables loose or even jumper cables.

The direction of the current flow through the system will cause at least a miniscule spark if you remove the positive first. With the hydrogen gas that hangs around the top of a battery, you can cause an explosion that way.

It's not nearly as dangerous with the newer maintenance-free batteries, but the older ones that had screw-in caps were REALLY dangerous and subject to exploding.

Another thing about pulling the negative first is the fact that you can easily short across the positive to ground. If you're using a wrench to loosen the cable, it's very easy to hit some metal surface with your wrench. If you have the positive cable off while working on a vehicle, and not the negative, there's always the chance that something will fall across the positive post on the battery and complete the circuit to ground. With the negative (ground) cable off, it would be nearly impossible to create a short unless you laid a wrench or something across the top of the battery.