Charging System Issues

[Fish_mojo]

We just got back from a two week journey in our 2006 Kodiak 22' class C Ford V-10. Before the trip, went out to start and the battery was shot. Checked the date codes and it looked like an original from '06. Installed a new 850cca battery and all was well. about 200 miles into the trip, the warning light for battery came on and stayed on. I watched the gauge cluster "voltage" gauge and could see it slowly dropping over time as we drove.

We pulled in for the night to a RV park and I checked the battery and it was down to 11 volts. fortunately, I had a charger with me and charged up overnight and got back on the road the next day. This time, the battery light was going on and off intermittently. When it got to a point at highway speed where it stayed off, it would go back on whenever the transmission dropped down a gear going up a hill and the engine revs jumped up. Once it dropped back down into cruising gear, the light went back out.

Finally got to our destination and was able to make it through the week by charging overnight or not using the vehicle. The trip home, the charging light stayed on mostly full time. I got home and there was not enough voltage to turn the starter over. I felt thankful we were not stranded.

Now, time to repair. Obviously, the charging system is not functioning properly. How to troubleshoot whether it is an alternator (highly suspect)or other component (do they still do voltage regulators or they integral to the alternator). I do not want to trial and error replace parts- how do you troubleshoot?

[2Bargos]

your alternator is/has gone bad. We have customers come in all the time with the same type alternator you have and their symptoms are identical to yours.

Chances are if you have it bench tested the unit will appear okay,
but once reinstalled it will charge for a short time and then symptoms will re appear.
If you have a rebuild shop available ask them to take a look at it for you.

[Trackrig]

Pull the alternator off and take it along with the batteries to someone like Autozone to be tested. If you need a new alternator, I'd buy a larger one (within reason) because there's a lot of power draw in today's vehicles that's hard on the minimal alternators the factory usually puts in.

Ask about the warranty on their various alternators. Some have longer warranties than others and by buying one from a nationwide auto parts place you can get a replacement even on weekends wherever you are if it ever goes bad again.

Bill