I am finishing up my w-t ground mod. I have been doing other projects and have forgot. So the 2 wires from the alternator one is the output that I am going to hook up to a circuit breaker and battery. But what is the other wire? Where did it hook up to? 

Not sure what that is. I have had both the Bosch and ND style alternator and the only wires either one had was the charge wire and the two field wires that plug into the back. I believe to blue wire coming out of the loom. Not sure what another larger would be unless someone added an additional ground from the case to the frame. Its not unheard of.

This is on a 98. It looks factory with a round crimp. 

Mine only had one charge wire that went to drivers side battery and now it goes to passenger side with a 150amp breaker. Where do your wires go to now? 

And if I were you I'd get rid of that fram filter and get yourself a donaldson. 

I havent hooked it up doing it today. But yes its going to a 150 breaker and the passenger battery. I am going to have to figure it out.

That series is a pain in the tail. Your going to have to modify that whole setup the charge lead and the two field leads. 

Are the batteries connected to one another? Couldn't you just run one charge lead to the passenger side with the breaker like an '01? 

 Crap, I keep forgetting, I need to install a fuse on the blue wire for the PCM. I forget until I see a post about the ground mod. 

Yeah I would most likely cut that plastic block terminal off and replace with a crimped ring terminals on the wire. Then use that positive lead from alternator to the circuit breaker and battery. 

Why cant i just cut off the wire and just run the charge wire and go on. I could just cut it close to the plastic block and put liquid tape on it.

The batteries are paralleled, (wired as one battery bank) which dictates that both batteries get replaced at the same time with the same manufacture dates whenever one battery goes bad.

 

There is some thought about running the charge lead to the drivers battery because that's where the battery temp sensor exists. But that's for another discussion perhaps. rRouting will be important keeping B+ charge wire away from the rest of the loom. Running to the drivers battery may require going up one size in wire gauge because of the distance. 

 

In your picture above you can see the stud on the alternator frame just nxt to one of the wires. That is for an external ground to the negative battery post. It is optional  and is always a good idea. Grounding, as the factory does, thru the mounting of an alternator mounting is rusty, painted, corroded and is a poor ground.

 

DieselFuture is right please toss the Fram filter and get Donaldson Blue if you can.

Edited March 21, 20214 yr by JAG1

That smaller gauge wire is a ground. So i can just ground it and hook the charge wire to my circuit breaker correct? But i still cant figure out where it grounded to or bolted to. The ring terminal on the end is half inch.

Yes, i am do for an oil change and I am ordering a Donaldson oil filter. Seems like a good oil filter

So the second wire is not attached to anything?

It come out of that junction and bolted to something.lol not my battery cables. I need a schematic. I need a schematic for one simple wire lol. 

1 hour ago, Doug Dear said:

Yes, i am do for an oil change and I am ordering a Donaldson oil filter. Seems like a good oil filter

I ordered a case a while back, down to few left, time to restock soon. 

38 minutes ago, Doug Dear said:

I need a schematic. I need a schematic for one simple wire lol. 

Here ya go.

Thank you for the diagram.

What year is your truck.  Early 2ed gens may have a wire harness that looks like this at the alternator.   Best to ohm test that wire to see if it is a ground or volt test if it power.

 

 

@Doug Dear

 

I have a 98.5.  I did the mod as instructed and left factory B+ unhooked and secured out of the way for the time being.  New charge wire to passenger battery.  AC noise is within spec for me. 

 

Look directly underneath your thermostat housing and you'll see where that ground terminates (the second wire in question).

 

Again, one goes to the PDC (factory charge wire) and the second (factory ground) terminates right underneath the thermostat housing.  

Edited March 23, 20214 yr by sooxies

Sooxies. Thats what I thought where it went. I'll be hooking it up thursday. Thank you.