I have been suffering from a charging system problem for about over a year now. At first I thought it was the connections on the batteries but after somewhat fixing them I would still have a slow crank in the morning. Now it has gotten to the point where if I use the ac while driving the truck barely turns on and yesterday I had to get a jump start at the drive thru, which is pretty embarrassing. I have 55w hids, a 250 watt amplifier that is not cranked all the way up, and a 3 gauge cluster. If I set my alarm for even 30 minutes the truck barely starts.

Now, this morning I checked the voltage from the positive nut on the alternator and when the GPR is running at idle my alternator is putting out 12.2 volts and high idle at 1300rpm is putting out 13.2 volts.
When the GPR is off I am getting 12.6 at idle and 13.65 at high idle. And monitoring through the obd2 port I never see above 13.7 alternator volts while driving. So I assume my alternator is done for? I even fully charged my batteries 4 days ago and they died already. I am a college student so I dont have over 300 to shell out on a quality alternator.

So my questions are:
1. Is my alternator bad?
2. Is a dbelectrical high output alternator the way to go for a budget?
3. Why are dbelectrical alternators about $100 cheaper on amazon and still have the 1 year warranty?
4. If I get a 200 or 220 amp alternator do I HAVE to replace the charging cable from alternator to the batteries?
5.Is dbelectrical still reliable these days since moving to China?

I was looking here this one is a 200amp for $240

And this one is a 220amp for $210 total. But why is it cheaper than the 200 amp on DB's website?

Any help is greatly appreciated I have already been late to work 5 times because of this so 2 more and im fired. Im tired of always asking for jump starts.

 

You might try some of these tests to assist you in your diagnosis.

Tools: DVOM, Carbon Pile Tester or Similar Device, Hydrometer.

BATTERIES:

Charging system problems often come to you as a "no-start" complaint. The battery will have discharged and the starter won't crank the engine. The first step is to test the battery and charge it if necessary.

No-Load Test:

Voltage Percent Charge
12.60V - 12.72V 100%
12.45V - 12.71V 75%
12.30V - 12.44 V 50%
12.15V - 12.29V 25%
(Readings obtained at 80°F)

ALTERNATOR:

1. Place the (+) DVOM Lead on the B+ Post of the Alternator

2. Place the Ground (-) DVOM Lead on the Alternator Mounting Bolt
You should see > 12.9vdc Minimum and 14.3 vdc Maximum.

3. Perform the same tests placing the (-) DVOM Lead on the Negative Battery Cable on the Battery, reading differing >.5vdc indicates corrosion or a loose connection which requires cleaning and.or repair.

RIPPLE VONTAGE:

1. Ripple Voltage Ripple voltage or (AC voltage) can be measured by switching your DMM to AC and connecting the black lead to a good ground and the red lead to the "BAT" terminal on the back of the alternator, (not at the battery).

2. A good alternator should measure less than .5 VAC with the engine running. A higher reading indicates damaged alternator diodes.

ALTERNATOR LEAKAGE TEST:

Alternator Leakage Current to check alternator diode leakage, connect the multimeter in series with the alternator output terminal when the car is not running. Leakage current should be a couple of milliamps at most; more often, it will be on the order of 0.5 milliamps. Use care when disconnecting the alternator output wire; make sure the battery is disconnected first.

 

Get your known original alternator rebuilt at a known local hometown type old fashioned auto electric shop. I had mine done this way as has been advised on here many times. a quality rebuild cost ME $5.00 LESS than the Chinese crap at the parts stores!

 

I do a lot of idling though so I dont think even a healthy stock alternator is enough for the ac + amplifier + all the trucks electronics?

 

Add a AIC or Chip with a 1,200 rpm idle or try a smaller pully

 

A rebuilder should be able to build your alternator meet the needs of your truck.

 

Let's just say I can't find a reputable rebuilder, because a lot of these shops are just looking to make a quick buck off of college students in this town. What do you think about the links I provided? I can afford those just nothing over the $300 range

 

I see the same problem with service members in military towns. If you roll into a shop with a DOD decal on your windshield the price goes up and quality goes down.

If I'm not mistaking the 6.0 alternator is rated at 185 amp. There are a number of threads on where where people have made that switch with minor or no mods. I don't have any experience with DB, but I did go through 3 AutoZone alternators in 6 months.

 

Go to a salvage yard, most salvage yards will offer a guarantee that the part works. They don't have warrantees, but at least you know the part worked once. Then take the ALT to a local parts house to have it tested. The salvage yard will usually pull the part for you because of insurance reasons and they don't want you breaking the stuff you don't want.

 

You didn't say how old the batteries are or how many cold amps. That a side a 06 alternator form o'reilies will work fine. You have to grid the bracket down in the middle but it's fine for a cheap up grade. You mitt even have to clock it to make a better cable fit. I like DC power alternators, but there have been some with problems out there. It's close to me but I've had no problems either.

 

Or, after clocking the alternator, place a few washers between it and the bracket and tighten the bolts down.

 

Batteries are exide batteries from tractor supply 750 cca one year old. When they fully charge they crank great but I noticed if when I start idling the battery voltage starts dropping

 

If you are short on cash, disconnect your batteries or buy two battery quick disconnects. You might have ONE bad battery, which will cause problems and drain the other battery/system.

 

Yeah, the symptoms you descibe sound like you have a bad battery to me. I have gone through at least 3 different scenarios just like you describe and only once was it teh alternator, the other times it was a bad battery. Get them load tested. If you see an Interstate truck, follow him to the shop he is going to and he'll do it and give you a print out. You can get 2 of their 850cca black tops for less than you are going to pay for that DB alternator that you may not need.

 

The alternator is the original by the way and the truck has 250,500 miles. I've had them charged 3 times at autozone and they always tested good but that's AutoZone so I dont know how reliable that is. Can I try switching the batteries around to see if that changes anything?