[QUOTE=Rainmaker1;21358158]That's another positive cable from the alternator post to the the other battery positive, it's disconnected in that pic as I was replacing the injectors.

 

Installed the new Mechman alternator this morning. It all went well.Now I'm no mechanic although have done an in-car 289 rebuild in a 66 mustang back in the late 1970''s. There wasn't anything I wouldn't attempt in those days. The very first thing I did and it was stupid of me cause I knew better, I tried removing the alternator power wire from the back of the OEM style rebuilt unit and was surprised with a little spark. Yeah I felt pretty stupid and luckily no damage occurred. I thought for sure I'd blown a fuse. Well then I proceeded to remove the negative cables from both batteries. Another lesson, I love those military spec battery lugs. It sure beats the old days of removing the lugs from the posts and deal with damaging them from removing and re assembling. Once the negative cables were off I proceeded to making the belt loose and removing the old alternator. Installation of the Mechman unit was a breeze. They include a wire harness pigtail that made the interface to the OEM plug easy. No cutting/splicing. Torqued the alternator to OEM specs of 35 ft-lbs and began making the new 1/0 pos and neg cables to the drivers side battery. The 300 amp fuse fastened to the positive military battery lug beautifully. I discarded the little red cap thinking it isn't really necessary. I still have it and may opt to install it later if I decide it's necessary. I used a hydraulic crimper from Amazon, pure copper lugs, heat shrink w/ adhesive, and appropriate color loom. The loom is one size too small but it fits nicely. It just doesn't close completely but that's ok. I also added a piece of heat shrink tubing on the alternator/engine harness positive lug where the shop who was there last just wrapped it with electrical tape. Rather than removing the tape since its integrity was good, I left it under the heat shrink. Maybe a little added protection, who knows...
After putting it all together before cleaning up I started her up. First thing I noticed was the glow plugs didn't hold the voltage down more than 20-30 seconds. I didn't time it but did notice the time was greatly reduced from before and the voltage went right up to 14.8 volts and held there steady for the entire 5 minutes or so I let it idle.
Overall, what a great experience tackling this job myself. The main thing I learned was by the time I bought all the tools and materials, time studying, cost of tools and materials and the time it took to do the job, I would have probably been time & money ahead paying a reliable shop to do the job. I do get the satisfaction knowing I did it and did it the way I like it, RIGHT! lol
The next thing to do is add an additional ground from the alternator mounting bolt to the passenger battery. I may remove the cable from the mounting bolt to the drivers side battery encouraging a circuit that includes Both batteries. I thing that's the point of 01_Excursions long negative cable from the alternator mount to the passenger neg battery terminal. In theory it's a great idea. I have the cable ordered and probably install that one next Saturday. Oh, it’s also nice to have a performance tag letting you know what the alternator output really is.
Well there you have it. With the help and generosity of the FTE community and special thanks to John in OkieLand, 01_Excursion, I'm very pleased and satisfied with the new alternator and experience. Thanks guys!

 

great install, I like that bright red wire loom.
no mistaking what that wire is...

I love the Military posts on the Passenger side,
on the Driver's side, I have a lot of accessories,
so I chose the Multi-tap version.
this pix is two years old, more stuff on it now.

 

Yeah I believe every wire, especially battery cables should be color coded. It looks like I might have a little more loom work to go. I’m wondering if when I add the ground from the alternator body to the passenger side battery if I should remove the ground from the alternator body to the driver side battery. My theory is by having the alternator body ground connection to just the passenger side battery and the alternator positive to the driver side battery, that the electricity would travel more evenly to both batteries. Of course the batteries positive is connected to each other directly. Kind of like a circuit of its own. Any thoughts on this?

I just went on some errands this afternoon driving about 30 or so miles. The extra output made a difference in how the engine runs. She has more pep in her step!
When the fuel bowl had a leak and replaced, I noticed an increase in performance. When the alternator wire was repaired before the new alternator, there was a performance increase. Now with 14.8 volts, there’s another incremental increase. The difference between 13.9 volts and 14.8 volts is definitely noticeable. Moral of the story, these engines are very happy with proper fuel pressure and voltage. A fuel pressure gauge is the next purchase along with a pyrometer. I already have the trans temperature gauge, just not installed yet. I’m waiting till I have all three so I don’t have to do 3 installations.

 

I replied to one of your posts that my crossover wire from my alternator to pass battery along the cowl wire retaining guide is a POSITIVE cable.
After you've driven it for a month or so, notate if the higher positive post on the alternator is creating any chaffing marks on the hood insulator. Since you have new body bushings I'm curious to know if this is going to happen.

 

To be honest, I missed that detail and relied on my logical sense. We may have different overall configurations since you opted for a new OEM battery cable system and I went with heavy duty cables from Custom Battery Cables. They did a great job making up all the correct lengths using 2/0 with he exception of from the battery to the solenoid and on to the starter they used 1/0.They call the 1/0 a "Hard Start" option. The positive cable between batteries is a 2/0 size.

Here's my logic... With the addition of a 1/0 from the alternator to the drivers side battery (+) and there being a 2/0 between the batteries positive posts, it's essentially the same as running a continuous cable straight from the alternator to the passenger battery (+). It's a direct connection to both batteries positive posts. Regarding the ground (-), running a cable directly from the alternator mounting bolt to the drivers negative terminal is a direct connection. I'm convinced so far that I have a great circuit, however the negative from the drivers battery has to rely on the engine block and ground connections to the chassis & body to make it to the passenger battery. There's no direct connection from the alternator base to the passenger battery negative. Hence my logic that a direct negative cable from the alternator base to the passenger battery would reduce much of the resistance of the path otherwise. Seems to me to be a more sound connection. To put it simply, the alternator has a direct uninterrupted connection to both batteries without anything in the path.

Your question of the alternator possible chafing on the hood insulation pad, I opened the hood and don't see any contact what so ever. What I did notice is the belt tensioner is at the end of its acceptable range. This is due to the Mechman alternator pulley being about 1/4" smaller in diameter. In the documentation that came with the alternator, they do not recommend swapping the pulley but rather changing to a smaller belt if it were a problem. I don't see a problem since the marking is within range.

 

the Fact of the Matter is,
with the heavy cable from Battery to Battery,
there is NO need for a charge cable from the Alternator to each battery.

the Charge Current to a Battery will never, ever, get even close to what the Starter pulls.

You CANNOT push Current.
you can only Supply Voltage,

each battery will only accept as much current as it needs during charging....
and that current starts to Diminish within minutes after the engine starts running.

just for the hell of it, I am going to put my 1,000 amp Clamp On ammeter on the Alternator output cable the next time I start the truck.

it will greatly surprise me, if the Peak Current Exceeds 30 amps.... for the two batteries together. I will set my Camera to Video Mode so we can see what occurs.

The biggest current draw is going to be the Winch....
that is the ONLY reason I went for the big MechMan alternator.

By keeping the Battery Voltage up at 14 volts or more, the Winch Current Draw is going to be Minimal for the load it is pulling.

what kills Winch motors, is to allow the Battery voltage to drop down low, say close to 10 volts...... an electric motor is going to pull Maximum Current at Low Volts....

 

I agree with everything you stated John. That is why I opted to install a direct ground connection from the alternator body to both batteries. Without that direct connection there's tons of resistance between the engine block and the negative battery terminals to both batteries. Basically I will have a direct connection to both batteries for both pos and neg battery terminals.

 

I have yet to do that myself.
the Power point DVM shows the batteries being pushed to 14.85 volts, so I am not going to worry about it.

The CJB is powered from the Passenger side battery, so it that battery has 14.85ish volts on it, the Driver side does too, as that is the only one with a connection to the alternator.

 

I haven’t installed the ground from the alternator base to the passenger battery neg terminal yet but what I have noticed is she runs like her a$$ is on fire. I find myself wanting to go for joy rides for no particular reason just because the fun factor is like never before.

What I’m trying to decide is if I should run the negative cable from the alternator base to the passenger battery along the firewall or between the batteries like the positive side routing.

What do you guys think?

 

I think you are chasing a Brain Storm

if that is what you want, go for it.

for me?

a foolish waste of time and money

 

It’s all done and I couldn’t be happier. I’m reading a constant 14.8/14.9 volts. Everything in the truck runs better, faster, and stronger. Just like Steve Austin!
As soon as these AAA crap batteries show any problems they will get dumped for a pair of Odyssey’s. Then I’ll be stylin’!

 

Clap Clap,
glad to hear your MechMan makes your truck happy.

I know mine runes smooth as silk at 14.9 volts