Batteries Not Charging?
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Batteries Not Charging?
Hey guys, I just picked up a 2000 f350 7.3. It had new batteries and lasted about a day before it died out while driving. I can jump it and get it started but it drains the batteries when driving. I replaced the alternator but still having the same issue. It won’t charge. The alternator outputs 3.5v with the wire harness connected and the battery light on. Disconnecting the harness turns off the battery light and it outputs 11v. The A circuit (OG/LB) has the battery voltage coming through and the I circuit (LG/RD) has voltage when the ignition is on and I have a jumper car connected.
I don’t really know what to do from here. I’ve tried 3 alternators so it’s definitely not that and checked fuses. Wondering if anyone had a similar issue and knows a fix. Thanks guys, I appreciate any help!
I don’t really know what to do from here. I’ve tried 3 alternators so it’s definitely not that and checked fuses. Wondering if anyone had a similar issue and knows a fix. Thanks guys, I appreciate any help!
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The Tech Folder at the top of this forum has many resources, one of which is this article that tells you how to test your charging system.
FTE Chapter Leader
Joined: Jan 2005
Posts: 13,113
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From: Henderson, NV
Are the batteries connected at the time of measurement? What grounding point did you use?
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Batteries are connected. With truck off the terminal is the battery voltage (11.8 now) and truck on it is 3.5v. I used the alternator block as ground and the negative battery terminal and got the same readings
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I just checked. Alternator case to battery is <.3ohm for both batteries.
i noticed the cable to the alternator and the positive terminals on the batteries do not have continuity but it still reads 11v. Is there an inline fuse or something on that cable?
i noticed the cable to the alternator and the positive terminals on the batteries do not have continuity but it still reads 11v. Is there an inline fuse or something on that cable?
