Hello All,
Recently became the owner of a 2000 7.3L F350SD crew cab, long bed. I am new to the world of diesels and am trying to learn as I go. Lately I have had an issue that is concerning to me, but prior to dumping a lot of money into something I’m not sure about, I want to see if there is a general consensus to my problem.

I searched the forums and found similar issues but not the “same” as mine, so here it is.

The truck starts fine, but soon after starting, the BATTERY light comes on. After about a minute it goes back out. The light coming on is more prevalent when I have not driven the truck for a few days. If I take a trip into town, shut it off, do business and start it up to come home, the light does not come on. The exception to this is if I have to turn my lights on. Then it comes on and goes back out after about a minute.

The date on one of the batteries put it at about two years old. It might be a bad assumption that the other one is the same. I will look at it today.

<OI live in Washington State so I don’t think the temperature is an issue on CCA.

Where or what would be a good place to look or check. Something I can do myself prior to taking it to a professional?

Thank you for your time and input.

Respectfully,
Mark

 

First thing to do is a load test on both batteries, individually. That pretty much tells you everything you need to know about battery condition.

Incidentally, you should always replace them in pairs on a Powerstroke.

 

That sounds like it needs to be done by someone with the proper equipment. How bout a Les Schwab or other "reputable" place like that?

 

Any place that sells batteries can do a load test for you. They have to do that as part of their warranty. Just make sure that they do each battery separate, and not while connected to the truck. Probably best to carry them down there with you. Or else take the tools to disconnect them. The dorks at the store will want to do it on the truck if given the chance.

 

Perhaps your alternator is on its way out.

 

Yes, Les Schwab can test your batteries, and probably your alternator also.

 

Hi All,

I wanted to share an update with everyone. It is probably accentuating the obvious for the seasoned vets here, but might help the "new to diesel" people like myself.

I did some observations and found that on the first start of the day, it took about 15-30 seconds for the BATTERY LIGHT to come on. After that, it took about 45 seconds for the light to go out. Keep in mind that before cranking the engine the Battery Light would be on, after crank it would go out, then come back on 15-30 seconds later.

During the start process, from key into ignition, waiting for Wait to Start light to go out, through the battery light extinguishing, I watched the Battery Charge Indicator (for lack of better name). When key was place to “wait” position the meter would go to a lower than normal position. Normal being what I would see when driving around etc. It seemed to remain in that position even when the Battery Light came on. But after the Battery light went out, the meter would jump to where it normally sits, indicating all is well.

Here is what I “think”: The times (in seconds which equal about 2 minutes) is roughly that of the time the glow plugs remain energized during the start sequence, assuming oil temp and whatever other variable dictate them to be on.

This would seem to indicate that I have a charging problem….This is where you vets say “No $&!T”!!!! I get it, but I’m a little slow in getting around to things. My truck has a SuperChip in it and as such, I realized I can check error codes. Plugging it in revealed a P1105, which indicates an Upper Alternator. I cleared the code and started it up again, and no light came on, because it was already warm I assume and glow plugs didn’t need to be on that long. Ran the test again and no code. The next day went out and started it, light came on, and code was present once again.

I have come to the conclusion I need to take it in and have a smart person with the right tools look at this…..Another “No S$!t” for the vets…….

How reliable are those codes? If it says Upper Alternator, is it going to be the upper alternator?

I can do the alternator myself but want to make 99.9% sure it will fix my issue, although nothing is a guaranty…

Thanks for your time and [input].

R/
Mark

 

No one has yet mentioned the most basic, simplest, and most informative test you can do to see what's up with your charging system/battery/batteries. Check the voltage between the pos. and neg. terminals of the battery with a digital multimeter (if you don't have one, stop what you're doing and get one) with the engine off. It should read right around 12 volts. Then start the engine and take the same reading. It should be in the neighborhood of 14.5 volts, indicating that the alternator is working. If the reading stays the same, or is not significantly higher than 12 volts, the alternator is not working properly.

For testing a battery, the best device you can have is a Midtronics Digital Battery Analyzer; I have their Micro400 model, and I don't know what I did without it. Got it on CL for $150, worth every penny. It uses no batteries, just runs off the battery you're testing; requires just 5 volts. You enter the CCA of the battery you're testing and hit the test button. Within 30 seconds, it electronically load tests the battery and tells you if it's good and charged, good but needs to be recharged, or simply needs to be replaced.

As for your question about how reliable the codes are, I'd say they're usually pretty good. Sometimes you have to weed out codes that are obviously meaningless, like for equipment that you don't even have (this happens a lot when I read codes for my Dodge van via the blinking CEL), but if it's saying you have a bad alternator, you probably do, especially based on the symptoms you've reported.

 

Before I go try this, there are two alternators. If one was bad wouldn't the other still put out 14.5 volts and wouldn't I read that since they are connected in parallel? I know that once the Battery lights goes off, it then reads 14ish volts. I will try it again this morning as per, and give results back.

I'm probably avoiding the inevitabe. I am fine with the inevitable, just don't want to change things because someone (not anyone here) thought it was a good idea and it doesn't fix the problem.

Thanks,
Mark

 

I'm going to plead ignorance on the troubleshooting of a two-alternator system since I've always been a one alternator kinda guy.

The best thing you could do is to find a local reputable auto electric shop that does nothing but rebuild alternators and starters, and test and sell batteries. I'm very lucky to have such a shop a quarter mile from my own shop. I can bring them an alternator or starter and they'll bench test it for me for no charge; eliminates all the guesswork.

Maybe someone on here more knowledgeable than I can tell you how to further troubleshoot what's going on with your truck, but it wouldn't be a bad move to take off the upper alternator and have it checked out by someone like my guys, and not just some parts place.

 

John,

Thanks. At some point I look at all this and equate time to money and frustration to all the other variable that tend to lend themselves to a situation like this, and think that the safest is to do what you said.

I will update as needed. It might help someone else.

r/
Mark

 

OK, just talked to my guys. It's pretty simple really.

Since you have two alternators, if either one of them is working you'll get the higher voltage across either battery when the engine is running; you just won't be getting all the amps. Simple test, requiring just the digital multimeter; just unplug one of the alternators and check battery voltage with the engine off, and then on. In your case, unplug the lower alternator (whichever one you don't have a code for) and see if you're getting 14.5-ish volts across either battery. If not, end of story.

The time, money, and frustration of which you speak is the exact reason that anyone who owns a motor vehicle should have a digital multimeter (about $30 for a decent one), and ideally a digital battery tester. Much better than throwing expensive batteries, alternators, and starters at a problem.

 

It was the upper alternator that was causing my problem. Now, afer the initil crank evolution the Battery Gauge pointer goes to where it goes and stays there, no movement throughout the rest of the GPR evolution.

Thanks again to everyone here!!!

Now on to other learning adventures with my new beloved truck