Hey Everyone,

I just found out yesterday that my alternator is on its way out. RMBC Freeride was kind enough to suggest a great alternator for the truck - 200AMP unit. It says with the instructions to install a 4 gauge wire for optimal charging. Has anyone done a write up on this or could anyone provide some pictures of the wire installed?

Also, I was cleaning the clamps yesterday and they seem to be REALLY flimsy. Has anyone installed new terminals that are more robust? Suggestions of what to use and where to get them would be much appreciated.

Cheers,

Rob

 

Talk to "gearloose1" over on the 6.0L section. He has more information about that than you will need to know.

 

I'll move this down to the 6.0 forum, but first...

My old terminals were tight, but not tight enough and ended up killing two alternators. I hacked them off and replaced them with the super heavy duty ones from O'Reilly: Super Start SK7001 - Battery Terminal 2004 Ford Excursion | O'Reilly Auto Parts

 

Alright..

Here are my quick thoughts:

i) gauge is a function of current / voltage / and distance.

Go to my signature thread, and there is a calculator in one of the posts.

Do the math --- and then add about 20% extra for safety margin --- corrosion, etc.

i.e. if you run 20 ft vs. 5 ft, there are different requirements.


Be sure you use top grade ends and also cover the wire in a loom / additional conduit so if the insulation fails, you don't fry batteries, whole electrical system, and start a fire.

Note the factory Ford dual battery is done with precisely that --- an outer wire loom, and insulated cable.

Don't take chances with vibration, salt, and all the other nasties on the road.


ii) alternators

If you are into serious sound equipment, there are other sites that have real good stuff on what it takes to power top grade systems, we are talking about battery, alternator, wiring upgrades.

I need more details to work on.. anticipated load, etc... RMS estimate of actual load, whether you are mostly highway, city, etc... and basically how hard you are going to be working the electrical demand on your vehicle.

If you are running it off a DC-AC rectifier, then you got to factor in losses (100% is not uncommon) so you take the "native" load, and double it just to start.

Cheapie power converters vent a lot of heat, and put out square vs. real sine waves... another consideration.



Be sure you get a real good alternator --- long story here about bad remans and factory alternators... we can talk more about this as you go on.

Typically, you are limited to 200a for a factory alternator setup before you have to go to things like oil cooling.

Well before that point, alternators crap out from heat --- on the electronics.

A clever arrangement is "outboard" rectifiers that have their own fan cooling --- consider that if you are doing single alternator.

Dual alternators that are "paired" in a vehicle require complicated electronics to control to ensure that one alternator doesn't do all the work and the other loathes.

Better is a dedicated alternator for hotel if you are really running serious hotel loads (like an ambulance)

In any case, you are into 200 amp max output.... work that out... that is about 2kilowatt.... per alternator... how much power do you need?




While you are at it...

Replace the pigtail in the alternator --- most frequent cause of failures (and good alternators chucked when it is a wiring fault).

You really need to sit down, calculate how much of a load you are running (how often), i.e. peak etc.

Then present the math -- and ask how much energy you need, how much overhead (safety margin), and how much for future expansion.

Then you go back to work the numbers as to what size of alternator / battery to support that... and then what wiring... etc.




Car manufacturers / commercial suppliers are in the business of minimizing use of raw materials like copper, etc. which have gone up a lot in price.

The reality is, a conductor is a conductor, and there is no way to skimp without losing out on capacity and safety margin.

When you are rebuilding --- you have the opportunity to do it right and spend the $$$ that the commercial shops can't afford to spend.


So do your homework, add in lots of safety margins, and go from there.



BTW, your best source for real heavy duty stuff....electrical wise.

Dealers for golf carts (electric vehicles), solar power equipment, industrial electrical / battery, fork lifts, etc.

These are proven industrial grade applications that are "life and death" applications and will not let you down --- unlike the auto grade stuff.

 

I've used those. The problem I had with them is the bolted cross bar. It's not heavy enough and keeping a long term good connection there is a pain. Ended up going back to factory crimped and molded cables.

 

What that is is an old fashioned one --- from before they went cheap with stamped fittings.

The old fashioned lead ones worked real good.... and is standard equipment in electric vehicles.

An added benefit --- there is not galvanic corrosion between two dissimilar metals.



Check this site out for the kind of fittings you want --- you can probably buy them locally:

Automotive Wire Terminals - Battery Cable & Electrical Supplies


Fuses everywhere is a great idea.





They also have pre-made cables with the lead connector at one end, and the eye on the other..

 

Awesome information - thanks so much! The image of the battery terminals is exactly what I had in mind and I like the idea of similar metals to avoid corrosion.

DB Electrical was suggested as a good place to get an alternator. Thoughts?

I'm not planning on running some crazy stereo system or a pile of accessories. I plan on installing at most 2 amplifiers to run the speakers and a couple of subs to have clean sound - not a loud setup. Will be installing a 13" dropdown screen in the rear and two 7" headrest monitors and I will wire in a 1000W inverter to be used to run a PS3, charge a phone, whatever. A friend of mine runs almost an identical setup to what is described above in his Suburban, has the stock alternator in it, and he has had zero issues. From my research the stock unit is 130 AMPS.

So my thoughts are to go with a 160 or even a 200 AMP, upgrade the battery terminals and the alternator wires (fused). Does this seem like a reasonable approach?

 

Good site, book marked, thanks gearloose

 

I guess for the fusable links from the alternator to the batteries, a person would need two of them as there are two batteries...