Dual alternator pin out
 

Ok so I did not disconnect my battery when removing lower alternator. My mechanic said I do not use alot of amps and could live without the lower unit. I did have some sparks when removing unit. I had a hard time removing plug. One wire pulled out of the harness. Charging system has been compromised. Did I blow a fuse? What should I look for? Only 12 volts at battery. I'm thinking I fried the top alternator. Can I just replace the internal regulator?
Thanks Bruce

01 E450

Can't help you with the wiring but I would definitely check the fuses to be safe.

Most alternators have the voltage regulator integrated into the unit these days. If you don't want to get a new one you can take it to a local electrical shop to see if the can replace the regulator or rebuild it for you.

I went down that road awhile back and did not get a warm fuzzy from any of the shops I talked to, plus the price they wanted to do it was not much cheaper than just getting a brand new one.

There's are fusible links between the alternators and the battery... you may have blown those...

fuseable links
 

That is where I am at now. Thinking I have fuseable link issues. I will check tomorrow to see if I have voltage at the plug. I do have voltage at top alternator and 12 volts at positive post of upper. I know I have no voltage at B+ terminal of second alternator . I have to trace where it leads before getting to battery.
Does anyone know what the fuseable links look like

I think I got this figured out at this point, voltage at both alternators piggy back each other

The Second Alternator is not loaded until the Primary Alternator exceeds 75% -
80% of its capacity (Amperage). Therefore, it is free spinning.

The Harness is interconnected to the Primary in a single molded Harness. If one is disconnected, the other will not work - It's Closed Loop. There is a way to close the loop but I'm having trouble finding the Connector View. I will look later - Very Busy Day! Two 6.0L Jobs. May get back on later this evening.

To save yourself $1000.00 or more for parts only:

ALWAYS disconnect the Negative Cables BEFORE working on the Electrical System. Among things that are very fragile to electrical current spikes, the PCM and GEM.

Throw the Keys in the Woods when performing Electrical Work. NEVER leave them in the ignition - Ask me how I know!

That is an awesome thread. I really got the concept of fuseable links.
Thanks

I dont think I want to ask why you should have thrown the keys in the woods I have a feeling it cost you alot of money.

You are starting to make me feel like I may not have to much damage being the ass I am(I can take this out with out touching any metal..."wtf was I thinking...I know better than this, Oh **** I am ****ed...Time to clean up my mess now")

Just took the alternator out of the top. The new one I have is incorrect so I might as well have them test it now. This is a new revelation that it is a closed loop and adds some wait to my uneasy feeling. The dummy light does not go one, I have gotten home the last three nights without dying on the side of the road. Charging system does not show signs of charging but it is staying alive. My gauge on dash stays in acceptable range for me but my digital gauge in the information box gets as low as 11.2 yesterday causing me to retreat with no heat and turning headlights on and off as needed, by the time I stopped to get fuel new alternator leaving truck running digital reading was back to 11.8

The Alternator (Open Loop) will not activate the Voltage Regulator unless the Circuit is competed (closed loop). There are three pins on an isolated Alternator.

(+), (-), and (F).

The Dash Lamp (which has its own fuse), goes off when when the circuit with a Diode is energized, closing the Field Circuit, which, in turn, closes the Voltage Regulator sending Electricity to the Vehicle and Batteries.

I still am looking for the Connection Di gram. You will have to cut/splice two wires for the Second Alternator or the Primary will not allow current to flow from the (B+) Post


https://cimg1.ibsrv.net/gimg/www.for...2119d12bd9.jpg

If you look at the Schematics (earlier post), you will see the Lamp Indicator and wiring.

Keys, Long Story Short: I had a Job that payed $600. When I was done, it cost me $1,200 from my Pay Check.

Here is my update. Alternator system has been fine for 2 years. I have been concerned for the last couple of days about the pin out of the lower harness, today I discovered that that harness is not even plugged in. I have not located the destination of the B+ terminal I am going to have to remove my battery to locate where it is going.
I hope you can find the diagram. What I am not understanding is based on what I have explained to you in this post how connecting the B+ lead to the second alternator would complete the loop. My son Grant is making this post for me sense I am trying to go to work today with the truck so I am not sure if you have sent the diagram but I will check when I get home. Thank you

I am now home and what a crazy day. The ford information center gave me voltage as low as 11.8 but actually hung around 12 and went as high as 13. The only other thing I am thinking... what is the ground wire connected to the lower alternator. I never connected it!

I had to run wipers and lights most of the day as well as the pumps I use to vacuum my tank to collect veggie oil, they pull about 12 amps, and the heat.

Personally, I make a Negative Cable and run them from the Alternator CASE BOLT to the Negative Terminal for both.

My new alternators came with a case bolt but my OEM ones did not (but the bolt hole is there). I'm not sure what the size/pitch of the bolt hole is but you can add the case-to-negative cable to your original alternator(s) as well.

I ran a ground wire from the alternator mounting bolt to the grounding bolt through the driver side air intake plenum. So this is all wrong? :-X19