While you're route is the right one.. I am a' glutton for punishment.I chased around smilar issues for over a year. Drove me nuts. I had an alternator rebuilt as well as bought used ones. It would get better then get worse. I was avoiding buying a new alternator because an OEM one was a lot of money and everyone is always all "the ones made in china suck and fail!!!"
I ended up thinking I was getting a deal from Atlantic British and getting an "OEM one" from them for under $200. Turned out it said made in china right on it. I hooked it up and all the problems went away and I am always showing high charge rates. I used to dip down below 12V on my meter when idled at a light with the heater on high, radio, and headlights on. Those problems are no more - zero issues, none.
I think your 12.6 is stil low, but up to you. I would just bite the bullet and get a new alternator from AB to be 100% sure it wasn't a coumpound issue.
Tom
Did all that. Grounds are good.If you have a bad body ground and a good chassis ground the thing could be charging but the difference in ground will affect the voltage the cluster is seeing. I would check your grounds by measuring voltage from battery pos to a body bolt or ground. Then compare that to the reading you get from battery pos to the alternator case. Another thing I do is run the engine and turn on all the loads. Like blower brake lights heated screen heated seats. Lights on high beam. The whole shooting match. Then make those measurements.
Sorry, what did I describe?Hi, there is MF1 that cuts alternator charge to the battery.
The best way to destroy an alternator is by cutting connections when running. Alternator has coils that have an inductive load. When you cut connection, current they generate cannot find an outlet except through "puncturing" one of its rectifier diodes on alternator board. In fact, it is typical way for it to break. For example when brushes wear out and charge is interrupted suddenly, or when ground connection is cut. I would advise never doing tests like the one Discoclay are describing.
Regards
Checked and good.Check ground screw in frame´s engine suport. This connectrs ground between starter and chassis.
Regards
Sorry, I was referring to your first post. Disconnect while engine is charging.Sorry, what did I describe?
Ah. Yeah, newer engine management systems can be a little sensitive to that method.Sorry, I was referring to your first post. Disconnect while engine is charging.