Very weird question: exciter wire for alternator
 

I'm working on a 60's GM vehicle.

Like many of them, a 4ga Black wire goes from the battery to the starter, and from there a 10ga Red wire feeds the main fuseblock in the interior.

I would call that a "main distribution point". No?

When I was learning to wire a 3-wire Alternator setup, i was advised that if you have a distribution point nearby in the engine bay, connect the exciter wire to that distribution point, so when you are drawing a load with your accessories, your alternator is taking a reading of the voltage drop AT THAT distribution point and will therefore do a more precise job of maintaining proper voltage.

Would it be responsible to send the alternator exciter wire to the "distribution point" at the starter solenoid? or is that trying too hard?





Why I posted this thread to start with: I want to add a small auxiliary fuse panel in the engine bay--this aux fuse panel may experience a few medium/high draw accessories--and was going to power it with a 10ga wire, and was trying to figure a place to take power from, if not the battery. So then I thought, connect the aux-fuse panel to the distribution point where the alternator senses voltage.

But then I got confused, because I asked myself, "which is more important, the main fuse panel draw, or the draw from my aux fuse panel?"


then I thought, why don't I just centre the draw at the same point? Connect the 10ga for the aux fuse panel to the starter solenoid, then connect the alt sense wire to that same distribution block...


Whad'ya think?

(OT: I am also strongly considering installing a Ford starter solenoid, and using that as my base of operations)

Re: Very weird question: exciter wire for alternator
 

I can't give a definite answer to your main question, but my thought process concerning the Ford solenoid is the same:

Attachment 2415057

When I first got my truck I had an intermittent no-crank issue. If I went below and jumped the starter with a screwdriver it would always crank just fine. I added the solenoid and have had no issues in the 25+ years since. The small terminal strip beside it is for any upgrades I may want to add eventually.

Re: Very weird question: exciter wire for alternator
 

.

Without regard for keeping anything original, I did this: in cab accessories, mostly not high amp draw things, are fed from the BAT with I believe a 10g wire from the starter solenoid which is also connected to BAT via 10g.

Everything else was rewired to collectively get their electrons from a BAT BAR installed near the BAT. This includes headlight relays, audio components, ignition, EFI, fuel pump, VA blower fan relays, electric cooling fans and any other big amp draw system. ALT charge goes to the BAR 6G and the BAR connects to BAT via 4G. The remaining aftermarket wiring harness was left in place.

If I were running a 3 wire ALT, I would place both charge and sense leads on the central bar.

Hth,

-Kevin

Re: Very weird question: exciter wire for alternator
 

This site will assist you with the questions you have.

http://www.madelectrical.com/electri...esensing.shtml

The tech index.

http://www.madelectrical.com/electrical-tech.shtml

Here is a link to how I swapped to a higher amperage alternator with internal regulation. It also shows the factory distribution point and how I replaced it with aftermarket marine terminal post. Scroll down to post 468 to start.

Every 60's GM I've worked on has had a similar distribution point buried inside the harness. What year and model vehicle are you working on. Typically GM didn't use the starter solenoid post for power distribution after the mid to late 50's.

http://67-72chevytrucks.com/vboard/s...698377&page=19

Re: Very weird question: exciter wire for alternator
 

In our truck there is a point in the main or also refered to as the headlight harness, called the main splice. It does what you are speaking of. It is also the best place to wire in higher draw accessories so long as you don't over tax the lead from the main splice to the battery when alternator is not spinning and added accessory is running. Like radiator fans.

Re: Very weird question: exciter wire for alternator
 

Vehicle is '67 Cadillac DeVille

I have also noticed cars from that era use crimped junctions, but not this car.
Here's a modified pic of the wiring diagram, and I'll number and explain the largest power wires from the starter solenoid. From the solenoid they are connected using fusible links, then turn into:

1)10ga red wire feeds to ign switch.
2)10ga black/red wire feeds fuse panel
3)12ga Violet wire is starter solenoid activate wire from ign switch
4)10ga red wire comes from alternator and goes directly to blower relay

That 10ga B/R is the only feed for the main fused/unfused circuits. The blower has it's own special wire and 30a fuse and is not relevant to my OP.

I also found this different than what I've seen, I looked at diagrams for my 72' GMC, a 1971 Camaro, and 75 and '76 Firebirds, and they all do it the same, with a crimped junction or a separate junction block like our trucks use.

The caddy just goes to the starter, then to the fuse panel.


BONUS:Wanna know something else cute? I've been working on a headlight relay setup for the caddy but unlike our trucks and other cars, where the factory headlight harness goes to one side headlight, then crosses the rad support to the other headlight, the cadillac splits each side of headlights at the drivers side firewall, one side follows the drivers fender, and the other follows the firewall to the AC box, then to the passenger fender. The wires are crimped together where they enter at the firewall pass-through "block".