Haven't tested mine yet but looking ahead, is a 140 amp replacement enough. I'm not even sure what my current one is. It's a 2005 with camper package so I'm hoping it may already be a 140. Thoughts? p.s. I did do some searching but the electrical threads can take quite a bit of reading and weighing opinions some times. Thanks.

 

That depends.

1. What are looking for while the glow plugs are on? The 110a will keep the voltage at whatever the draw drop from starting and glow plug usage was, then will recharge the batteries as the vehicle is run with the GPs off. The 140a will be supplying about 95a with a creeping up voltage.

2. If your concerned about that initial voltage then a higher amp unit will bring the voltage up during this time period.

3. What are you drawing during normal operation and high load conditions?

Typically in a non-camper situation once the engine has reached its operating temp and batteries have recharged to this point you'll have about a 30a draw, then with everything on such as lights, radio, a/c on high, you can be pulling 65-70a at idle, so you have about another 20-25a headroom for accessories with a 140a. Off idle of course you can get up to the 140a.

So depending what else your trying.to power, when, and how often your trying to do it will determine your needs.

 

Just installed a new Bosch 140amp and so far so good. I had trouble keeping my voltage in the 13s with the old one even after I upgraded the cables and redid all connections and grounds. Now it sits at 13.8 at idle even with all accessories on. That's on my Dash Boss so it's probably closer to 14 right at the battery's. Good enough for me.

 

I had the standard alt. on my 2005 for ten years and never had a problem with the ficm or injectors. They did replace it on the 8th year based on a border line test. The truck was 100% stock so no extra draw.

 

I made it a little longer and upgraded just because.

 

I guess I made it ten years too! My FICM has all but bit the farm and has me wondering about the batteries (1 year old) and alternator. Plan to get both components load tested before firing up the new FICM. I don't run any high power lights but do pull a horse trailer on a regular basis and many trips over the years with campers. My Scangauge numbers have me holding my breath waiting for the voltage to come back during the glow plug cycle. Seems to run 13.5 - 14 going down the road but those first couple of minutes Thanks for all the feedback.

 

Basically you can't have too much power making capability. The regulator will limit the output to what is necessary if there is surplus capability. With the standard 110a unit you're border line underpowered even in the "best case" scenario. It does work ok if everything is in good order and you're easy on the system but the batteries often have a hard and typically shortened life.

For example, imagine you crank the truck in cold temp, glow plugs are on longer, you have the seat heaters on, stepping back into the house to let it warm up, you flip the defrost on high to clear the windshield and just for good measure, you turn the lights on so you can see better. The truck is at idle, limiting alternator output to less than what it's actuially rated. Any deficit is made up for by the battery. In most vehicles this deficit situation only occurs when the starter is engaged. Although I haven't done the math, I believe it's possible to get into an extended deficit with our trucks and a 110a alternator, at least until the glow plugs go off and possibly even longer. Now you make your 10 minute drive and shut it down. The short charge cycle doesn't bring the batteries back to where they were this morning. It's possible to do this twice a day for five days and the truck still cranks. Finally you take an hour drive on Saturday and the batteries charge fully. My point is that it depends on how you use your truck. If you live in a cold climate and want to be able to flip everything on and let it warm up, a upgrade is, without a doubt, in order. If you don't have a need for this the 110a may work for you.

Another situation would be pulling a camper. The extra lighting, camper battery charging and electric braking would add to the total load. AC power converters and DC coolers are common and can draw quite a bit of power also.

140 amp units are a good option for upping the power on a budget. It's possible to get 180a out of some models of the earlier-larger 3G case Ford alternator, another low budget option. The more expensive aftermarket units look sharp and make gobs of power if your budget is a bit larger and you have a need for that much power. Don't forget the wiring upgrades if you go above the 140a and load the system that hard.

 

I have a 110 amp. I've never had a problem.

 

I've killed a 110A and a 140A in two trucks. Battery health plays a big role in the overall picture. I also killed a 160A unit in a Jeep, so sometimes chit happens.

 

I bought my 2006 in May of 2010 with a fresh rebuilt AZ 110a alternator and one (?) new battery. In just a couple of weeks the battery light was flickering often, particularly at night with the lights on. I know a couple of guys at the lot where I bought the truck so I stopped back by and found the had registered the warranty so I pulled the alt and they ran back to AZ and swapped it for me. That one lasted a couple of months and I went to O'Rileys and bought a new 110 and charged/tested batteries, that lasted longer, maybe a year and change. Off to the local rebuilders who repaired my alternator and put a different diode tro and regulator in it. Replaced the batteries this time and got a couple of years+ out of it. This was a hot topic here at FTE at the time and I had read several posts about using the larger case alt. So when it died again I Had a talk with the guys at the local shop and they built me a 3G case alt with all the best parts they had. They threw it on the test bench when I picked it up just to show me what they had built- 183a at 1,000 rpm. Not too shabby. It's been on the truck for many months now with no issues and cost was less than $200 with tax. The only issue I had was they built it as a self-exciting, one wire alt so I will not be seeing the battery warning light on the dash again even if there is a problem, but I do run a ScanGauge full time so it's up to me to catch it now I guess. Currently battery volts never drop below 12.3 during start up and stays around 14.0-14.2 like a rock after a couple minutes of running.

If you get good parts they can last a long time, if you try to fix it with junk parts they can be a headache.

 

I just talked to a local auto electrical rebuilder with an excellent reputation and he said that while the 6.0 alternator does not have a high max output like some alternators, it will handle higher continuous loads. He said that that the 6.0 alt will handle 80% cont output while the higher output ones might only be around 50%. I asked about the Rams that have 180 amp, he said said they would both have about the same capacity continuous output. They are limited more by physical size that anything else.

 

Which 6.0 alternator is he talking about, the 110A unit or the 140A unit, or both?

 

Both alternators

 

In my years I never had direct contact with anyone in the sparky side of Ford but my inference from other areas is that I can see that type of a requirement, as well as companies involved as a commercial supplier, although not necessarily a boutique company.

 

You've already gotten some great folks input. Just to clarify: the Camper Package doesn't include the 140A High Output alternator. We ordered our truck new in '06 and got the Camper Package and also ordered separately the 140A alt.

We don't use the truck's alt to charge the camper, I leave it off and it gets charged through a large solar panel on the roof. Our trailer(s) however do get charged off the truck, but they rarely are connected on cold start. BTW, this would be a tip if you haven't already read it between the lines of the other posts: start your truck and add loads (as possible) After the GPM goes off...

Our original batts lasted 6 and half years and I wasn't as rigorous at keeping them topped off early on as I am now.

I also put the smaller (overdrive) pulley on and it definitely makes a difference, particularly on cold start, but also just at idle.

FWIW: Ford went to the 140A as the standard alt in '08...