The large black/orange wires are not connected at the alternator. The factory amp meter and shunt wire are still there.
The new ALT 4 gauge output wire runs to the battery positive. Power to the fuse box runs through the shunt wire.
See drawing here...
https://www.ford-trucks.com/forums/1...l#post14726314
The flow of current from the battery, through the shunt wire, to the fuse box, is is a discharge direction and thus the amp meter will show discharge.
The shunt wire is bypassed in the "charge direction" only.. meaning the amp meter will not longer show if the battery is being charged after you start the engine.
Power flow to the fuse box still flow through the fuseable link, through the shunt wire, to the fuse box. Which is the same route it would flow if the ALT failed while driving.
Jim

 

Your right. It's half bypassed.

 

I really appreciate all the information, but some of this went over my head. Does the configuration I showed in the crude drawing I posted work, or do I need to change it? And if I need to change it, what exactly do I need to do? Thank you very much friends

 

Should work. Your "green" is really red/green and is the ignition on trigger. The yellow is the 12v feedback voltage for the regulator. If you hooked your white/black up, that must be feeding your choke. Otherwise you do not need your truck's white. I believe the 3g has a short white jumper on it?

 

Yes, the 3G plug had all three wires and the white and black wire was jumped to the stator port on alternator.

 

Glad to hear I have this hooked up right. At least I know why the gauge seems to be working backwards now LOL. But I still don’t know why I’m getting this voltage dip where the RPMs slightly dip, the headlights dim, and if I have the heater on it also blows less for a second or two. This dipping voltage is not reflected at the battery load with a voltmeter on it. At the battery the voltage is steady. Battery checks out at 12.6 V when engine is off and just under 15 when charging and under load

 

Huh? Kinda late to the game here, but are you saying you're still seeing nearly 15v at the battery when the headlights go dim? If so, that doesn't sound like a problem in the charging system.

That seems more like a problem with power distribution, such as a loose connection. One likely culprit is the automatic circuit breaker in the headlight switch. If the voltage is too high (more in a minute), the headlights may be drawing just enough power to put that circuit breaker teetering on the edge of tripping. Maybe it's not quite enough for a clean trip, or the breaker is defective and only opening partially.

To test, run the engine to duplicate the fault for several minutes. Keep the dash lights at full brightness so the rheostat (inside the switch) is bypassed and not generating heat. Carefully touch the switch body to see if it feels warm. If it is, that indicates a defective switch.

Did you say the heater fan runs slowly at the same time the headlights go dim, yet you still have nearly 15v volts at the battery? I'd have to put on my orthopedic thinking cap to figure out that correlation, but that still points to a problem with power distribution, not charging.

Back to the almost 15v you measured. That's pretty high. Normally you want to see the charging system output around 13.75. I wonder if this high output has been cooking your battery and aggravating the situation.

 

Well, in the process of attaching an extra ground cable to the battery and frame to see if I had a negative cable problem, I decided to tighten the bolt on my negative battery cable as tight as I could. Voltage dip problem gone. At least for the moment. I’m telling you that cable was already on their tight. Containing the cable is tight as I could actually solve this problem?

 

That could ‘splain a lot.

Can you please post a picture of this terminal? Are the two ears parallel where the bolt passes through? Is there a gap between them with the bolt tightened? If the ears are bent, they may be touching each other, which greatly reduces the clamping force on the battery post, where it really matters.

With a proper gap between the terminal ears, I’ve never had to reef on the bolt. Snug has always been plenty adequate. Something doesn’t sound right if you have to overtighten the bolt.

I also wonder if the crimp within this terminal is bad. Perhaps tightening the bolt wasn’t the actual fix, but in the process the cable got nudged and made better contact. Wiggle the cable and see if the fault returns.

Did you ever run a ground wire between the alternator case and negative battery terminal? I saw some discussion, but don’t know the outcome. Not needed in a perfect world, but the one where I live has Nancy Pelosi. I’d run a separate ground wire for peace of mind.

 

If you want to test the main battery cables, pull the plug wire off the coil and crank the starter for a while and see if the connections get warm. Be careful if the connection is real bad it can be scorching hot.

 

This may sound backwards, but it's much easier on the coil to leave that end of the wire connected. Instead, pull the wire from the center of the distributor cap and ground the lead.

With everything connected as normal, the coil output only builds high enough to jump to ground, creating the spark (out at the plugs) that we all know and love. But if no (relatively) easy ground path is available, such as via the spark plugs, the coil output will build and build to potentially damaging levels. In some cases, it may find a weak spot, such as marginal insulation inside the coil, and create a new ground path. But if you ground the coil output, the voltage harmlessly dissipates and can't cause any damage.

Back to the suspect cables, you can also check them with a meter:

https://www.ford-trucks.com/forums/1...w-starter.html

 

A low ranging voltmeter is your friend here.

Remember this is a low voltage, high current DC system. Loose, missing, or corroded grounds, straps, and connections will confuse the regulator and cripple the alternator current output. Resistance is difficult to measure at such tiny values. And how much is "normal"?

So instead of attempting to measure resistance, the voltage drop along a single cable or between a connection while the circuit is energized is done. The voltage loss in a cable or connection will be displayed as a positive voltage, because the electrons find it easier to go through the voltmeter instead. I don't understand it, but it works great. About +0.2 volts total is the accepted limit for a ground system. 0 of course would be ideal, but there will always be some.

Place one probe on the negative battery post, the other probe on the alternator case, the grounded metal. Check it at idle and when spooled up, accessories on - headlights, and heater.

Same test on the positive side from + pos battery post to the alternator + terminal. Might see a bit more, 0.3 volts or so is the limit.

It doesn't take much of an increase in resistance to cause trouble. Let's say a 120 amp alternator operates in a circuit that has a normal resistance of 0.11 ohms. If that resistance were increased to 0.17 ohms because of a bad wiring connection, the alternator's maximum output would be limited to 80 amps. In other words, an increase of only 0.06 ohms (almost nothing!) would reduce the alternator's maximum output by almost a third! Under light load, the drop in charging output might not even be noticeable. But in a high load situation, the alternator wouldn't be able to keep up.

Voltage Drop Testing

Clean, tight cable connections on both ends are very important. One reason (among many) cheap generic battery cables are no bargain is the terminals aren't durable enough to be tightened more than once or twice without becoming deformed & loosening and then they are trashed. I've never used a torque wrench on battery terminals in my life, though I'm pretty meticulous about using them generally. One day I was messing around and decided to see how close my calibrated elbow was compared with the published torque spec on battery terminals.

Turns out they are reefed on pretty tight when torqued to spec. Then, noticed something I thought was interesting (Yeah, I'm easily amused) on the "percentage charged" display of the battery charger after say running the starter for a few seconds. The battery won't dip in charge level near as much as before torqueing them to spec.

Anyhoo loose connections are No Bueno. It's a pain in the you know what, but it pays to clean up the connection points at block, frame, and firewall. If the cables and ground straps are original or just kinda old (to vote, or buy tobacco) then they too should be replaced.

Clean, tight, shiny bright connections = Happy Electrons.