Stock Alternator not sufficiant for my ride do I need a high output?

Ralfaro

Registered User
Joined
Oct 6, 2013
Posts
2
Reaction score
0
Location
Royse City, Tx.
2004 Excursion 6.0L Powerstroke Diesel

2x Red 35 Optima batteries
1x Sony DVD/CD Stereo
1x stock DVD player in rear
2x ZX-4722 12" High Power Subwoofer 1200W ea.
1x ZX-5169 Digital Monoblock Amplifier 3000W
1x Kicker 700W Amp
Rear and Front AC/heating systems
Fog lights
alarm

my alternator is reading 14.4v with the just the truck and running lights on, but when I turn on the radio w/subs it drops to 11.9-12.0v please someone help me find out what size alternator I need... I am also planning to put a winch and light bars on as well...

thanx,
[email protected]
 

BioFarmer93

OPEC Hater
Joined
Sep 19, 2009
Posts
686
Reaction score
26
Location
Jacksonville, Florida
A Ford 3G 200A drops right in and is internally regulated to boot.. Best electrical choice I've made for a while. Plenty of threads on installs here, just search a little. Also- go oversize on the positive wire from the back of the alt to the solenoid and use a dab of NOALOX on all of the weather-exposed connections, it eliminates oxidation buildup from electrolysis and lowers resistance over the long term. It also doesn't hurt to find all of the ground points you can on your engine, firewall, frame and cab, then unscrew, clean and NOALOX those as well. Even your brake lights will be brighter due to lowered resistance.. One thing I have learned while reading here is that Optima batteries, through some business shenanigans are not the amazing things they used to be. Most folks here (including myself) that want serious starting and reserve wattage have gone to Group 31 size batts from the highest rated manufacturer we can afford.
 

snicklas

6.0 and Loving It!!
Staff member
Joined
Aug 7, 2006
Posts
6,164
Reaction score
2,342
Location
Greenfield, Indiana
I am not sure on a fix, but I agree with what was posted above. You can get a dual alt setup form an ambulance prep truck or van. But you also need to get all the wiring because of the dual setup.

Also, you could buy an "overdrive" pulley for the alternator to make it spin faster at idle.... most alts do not charge well at idle... I looked into this but did not choose this option because my batteries had failed, and once I replaced them, my "charging issues" went away.

Another option, you could do the "high idle mod". The 6.0 PCM has a PTO provision built into the programming. When you place +12VDC on the appropriate wire under the dash (or under the hood on the Excursion) the truck will kick the engine RPM up to ~1200RPM, if it is in park or neutral, some require the parking brake to be set. I have not done this because I was following the truck instructions and could not find the wire I needed. Talking to a Ford Tech, they did not pull that bundle through the firewall on the Excursion so I need to go find the wire under the hood. There are write-up's on the net of how to do this mod. Only costs a few bucks for a switch. Doesn't need a relay because you are just tripping a control wire, there is no real current draw in this circuit.

I would strongly recommend not running the engine with the voltage that low. The FICM is extremely sensitive to low voltage. If the voltage drops, you can burn up the FICM. It is an expensive fix, I have already been down that road. You have to keep the voltage up, and keep good batteries in it. With the electrical strain the 6.0 puts on the batteries stock, you can run into power issues very quickly. I had marginal batteries and didn't know it..... went through 4 alternators, 2 NAPA rebuilds, a NAPA new and finally a BOSCH which is still on the truck. I changed out the batteries out with 2 of the Economy batteries from Interstate and no longer had starting/low voltage problems. However, running the truck like this for an extended period of time, I cooked the FICM. The FICM (Fuel Injection Control Module) is responsible for stepping the ~12VDC from the batteries to ~48VDC to run the spool valves in the HEUI injectors. If you run the truck low on voltage, the FICM has to draw more current to still attempt to make the 48V needed. This in turn causes excess heat inside the FICM and causes either solder joints to fail, or cause components to fail. While mine was failing I was having trouble starting the truck, it had no power, smoked blue all the time (late timing) and finally the FICM quit all together and there she sat. (Fortunately it died while the truck was sitting in my garage). I had the FICM repaired from a place online to the tune of ~$150 dollars. If you get a replacement FICM or a "half shell" from Ford to fix the problem, it is a several hundred dollar part, and the FICM has to be programmed. Last quote I saw on a New FICM (entire unit) was $800+ from the dealer. Now, the first sign I have of battery issues, they get pulled and replaced. I got 4 years out of my last set, and I consider myself very lucky. Most of the 6.0 guys have said if they get 3 years out of a set of batteries they are surprised.
 

dsltech83

Full Access Member
Joined
Jul 16, 2010
Posts
428
Reaction score
0
Location
Ellery,IL
Yep get a DC Power high output alt. 6.0's have way too small of an alternator.
 

Forum statistics

Threads
91,217
Posts
1,128,479
Members
24,045
Latest member
Ramtough01

Members online

Top