Alternator advice?
 

Hey guys, I'm looking to swap out my alternator for a higher amp version and need some ideas of which way to go. What is the OEM model putting out amp-wise?

What is a good higher output model and where is the best place to get it? I don't mind running additional wires (in parallel) if need be to accommodate the extra juice.

Thanks in advance guys!

110 to 120 depending on model.

The key is not to buy by amp (theoretical max output) but by duty cycle based on what you have hanging on it.

A) Begin by estimating your total electrical load

B) Add what add ons, unusual operations you have that raise the load

C) Then size an alternator that is a fit in terms of:

- RMS output (not peak that it might sustain for 100ms)

- @ relevant RPM and temp (Hot alternator = lower output)

- Duty cycle

Notice no major high volume alternator vendor will talk about duty cycles of their product.

So you are left to guess who is for real and who is blowing smoke.

If you are really into Heavy Duty --- an Ambulance grade alternator.

Max you can do without liquid cooling is about 200amp continuous.

But don't overbuy... buy what you need with a safety margin.

If you significantly up amps, you have to upgrade cables, fuse it, etc.


I deliberately went for a lower amp alternator (145amp) that had a high duty cycle (close to 100%) and not upgraded cables.

I just spent 20 minutes talking to DC Power about their alternator and discussing various technical aspects of their products - including duty cycle. I talked to Robby. He was extremely helpful and I was impressed w/ his knowledge and experience. They clearly have a solid product. He talked about failure rates as well. Their 190A alternator is what I run. Robby talked about the design of that alternator and said it is the same platform as their 250A heavy duty alternator, just smaller shaft and bearings. They have virtually no failures in this particular unit because of its components being based on the higher amperage platform.

Ya, I know their stuff is good.... that is why I don't think their alternator is at fault at the moment.

Just wish manufacturers will release their engineering data!

LOL.. fat chance.

I hear ya!

If I am harassed enough, I can put up a basic spread sheet to calculate your vehicle's baseline load, then what amount to add for accessories, add ons, load factors, etc. and how to size an alternator properly for the right mix of peak power, duty cycle / load factor, etc.

Basic electrical tech stuff... not rocket science.

That sounds about right for me, my truck is standard and has no powered accessories other than the usual radio and the other OEM stuff.

So where would be a good place to go (online or brick and mortar) for such an alternator?

If you are plain, OEM, no unusual loads, your easiest bet is to go to partsguyed.com and ask him for the exact part number (no substitutions) for your factory OEM replacement.

Ford makes both new and reman, you can shave a few $$$ there.

Be wary of parts counter guys that give you an "also fit" and often, charge you the higher price.

Why waste time and money on a big / expensive part that you may not need.

My factory alternator lasted 200,000 miles before the bearings wore out.

The first non-OEM replacement (not me) lasted less than 1 year.

Give DCPower a call and ask for Robby. Talk to him about their product. You can also do internet searches on audiophile sites - the DCPower alternators are highly recommended.

Very satisfied with my DC 185 alt. have not had it too long, but has worked flawlessly and I feel good about my investment.

Thanks guys, I'm going to order up a DCPower alt. I've gotta pass some rep around but I'll rep you for the above posts!

Bis/Gear Think their 185 unit is overkill? https://www.dcpowerinc.com/fit/2004~...7-185-oem.html

It's the lowest amp model they have.

You can't go wrong with that one... I would think of a cable upgrade at the same time.

You can put a second cable side by side the existing one, but it must be individually fused.

IMO this is the way to go with the low failure rates on them (based on some other forums and the manufacturers claims), the high output at idle, and the identical design patform as their 250A units (even at max output, it will operate very comfortably on the design curve and won't be stressing internal components). The only drawback is the price. Gearloose might have connections for re-building to better specs at a cheaper price, but I am convinced that this is the way to go for those of us that aren't "in the loop".

Connections to get a top grade rebuilder:


Welcome to the Electrical Rebuilders Association!

You hit these guys regional members closest to you and start asking who is the most reliable / best reputation in your area...

Eventually, you will find them.

If you really do well, you don't pay a lot either... but you get the best of the best.

Who is usually a small shop.. don't advert (no need to) but they do all the tough work for everyone... and have a months long backlog...

You stand in line... and beg.

Nothing like talking to the fella who is building your alternator... and who can pick and choose parts from his inventory to fit your needs exactly.