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imageHi all, or should I say Y’all I am always amazed at how often I need to use my CTEK mus4.3 to charge my battery in my roadster. It’s not a new thing but today I had to use my hand to push me down a hill to get it started, which it did in a flash but it got me thinking I better set a reminder to put that thing on and maybe after 5 years I should do some checks on the alternator to see if the output is good I seem to be talking very small rides lately as we’re still in prison here pretty much and the charging of the battery never gets to full charge.  Appreciate any suggestions from the brain cloud




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Last edited by IaM-Ray
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What battery are you using? What is your charging voltage, engine running, above 1500 or so? Anything between 13.8(bare minimum to keep it charged) and 14.7 is good, depending on electrical load.

Subaru engines seem to be VERY sensitive to proper clean grounding in order for the charging circuit to work well. I ran a couple extra ground straps on my wife's Subaru and haven't had a problem since. Check difference in voltage at the alternator output AND the battery. Any more than 0.1 volt difference indicates a battery cable/ground problem.

Also, since you've added all those modern-day gizmos, maybe one or more of them is drawing a little juice all the time, killing your battery softly, you know, like the song...

To test, remove ground or positive(your choice) and put an ammeter there in series between the empty post and the terminal you removed. You'll find out if there's any kind of draw/short.

Finding and fixing a parasitic battery drain sounds fairly simple in concept, but can be very difficult in application.  Lots of online tutorials, youtubes, etc. on what to do.  Most of them follow the same principles.  It can be much more difficult to assess without an accurate wiring schematic.  If you don't find the draw in one of your circuits, which you will disconnect one at a time, watching your multimeter for milliamp fluctuations, don't forget to check your alternator diodes.  A bad diode will allow current to flow in both  directions.  A rule of thumb is anything over 85 milliamps needs to be corrected.  50-85 mlA is normal in a modern car, less than 50 in older cars, but our replicas are all over the board regarding add-ons, geegaws, sensors that stay active, even with the key off, etc.

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