Electrical Mayhem, Help Needed

[crash-harris]

After asking and finding out what to do with the voltage regulator for a 3G swap, I think I may know why the battery light came on for a millisecond last night. The factory charging wire goes to the voltage regulator from the output lug on the alternator. The terminal has been cut off by a PO and a 4 gauge or so cable put in its place directly to the strarter relay.

This will change soon when I do the 3G swap. I was going to hock the stock alternator on warrenty for Bruiser's 3G, but the inline sixers do well with the 12:00 clocked case from a '95 3.8L V6 and it appears that the 3G from a '92 Econoline inline six is clocked better for the v-belt brackets on the IDI.

I'll still hock the Bronco's alternator on the warrenty for another 3G for its inline six, but I'll just buy the clocked version for the Enterprise D

 

[franklin2]

The factory charging wire goes to the voltage regulator from the output lug on the alternator. The terminal has been cut off by a PO and a 4 gauge or so cable put in its place directly to the strarter relay.

That statement is correct in a way, and incorrect another. The factory wiring has a large charge wire that goes to a splice in the wiring and eventually ends up at the battery +, just like the 4 guage wire does now. That's your main charge wire. The wire going from the charge wire to the regulator is a small wire. The charge current does not go through this wire. You can think of this wire as taking a "sample" of the voltage in the wiring and the alternator, and this wire goes to the "A" terminal of the regulator. This wire gives voltage info to the regulator, and then the regulator uses the "F" terminal to control the alternator output.

So while there is a wire going from the alternator output to the regulator, it's just a small signal wire with little current going through it.

 

[crash-harris]

Then I should probably get a ring terminal on it and get it reconnected to the output lug on the alternator then. Like I said, a PO had cut it off and taped it, leaving the orange rubber cap on it just hanging out on top of the alternator, not contacting anything.

 

[fsmyth]

Granted that not everything I have worked on in the past has been a Ford......
I will stand by my statement. Abuse and/or modifications (extra lamps, trailer wiring, etc.)
seem to me to be the biggest cause of failure. Of course, after 20 years of use, I would
not be surprised to find some that are just worn out. And poor contacts generate heat.

 

[madpogue]

Abuse and/or modifications (extra lamps, trailer wiring, etc.) seem to me to be the biggest cause of failure.

Extra lighting and trailer wiring may be "mods", but they're hardy "optional". The OEM headlights are downright dangerously dim in today's world.

Of course, after 20 years of use, I would not be surprised to find some that are just worn out. And poor contacts generate heat.

This. Of course, most mfrs would argue that anything on a vehicle lasting 20 years is not "underengineered" as I described above. Henry Ford himself sent engineers out to the scrap yards, as his first generations of cars were finding their way there. Not to see what failed prematurely, but what didn't. IOW, what outlasted the car otherwise. He deemed those components as over-engineered, and cheapened them. The industry has followed suit to this day. So by that standard, no, I suppose the lighting is not under-engineered. Of course, this whole section is dedicated to trucks older than that, so I suppose you could say a different standard applies here. Or at least a different approach to engineering / re-engineering does.

 

[fsmyth]

Well, they obviously found that the FSS and the ignition switch were over-engineered
On my '91, the fuel tank selector switch would occasionally blow the fuse. Took it apart
and found that the contacts were so worn that they wouldn't stand straight. Therefore
was a dead short at times. It was so cheaply constructed, that I just replaced it with
a standard DPDT toggle switch. Hard to see how a tank selector could be that far gone.
Same with the ignition switch. After disassembly, it was so obviously worn that it was
no surprise WHY it was intermittent. And it was a small shock to find out how cheap
the auto store replacements were. At least you can afford to keep spares

BTW, the light switch and connector was fine <grin>
And this on a truck with 4 side markers, cab lights, small fog lamps, separate
brake/tail lamps, and a trailer plug. Looked like the original switch to me.

 

[crash-harris]

Looked like the original switch to me.

It had but connectors on all the wires and one had fallen out apparently and had been replaced with a standard blade terminal that I had to disconnect after pulling the plug

I did reconnect the black/orange wire to the alternator output lug today.