I have a '00 Ford and have trouble starting it. The battery reads 14.6V while running. Immediately after I shut it of it reads 12.6V. Then within 20 mins it drains down to 10.5V and doesn't drop any further. I believe this could be a relay. I'm hoping it's not the battery since I just got a new one this past winter. Any ideas?
The battery probably has a bad cell. If so it should be under warranty
I agree I think it is the battery. I pulled all the fuses and relays and none of them were bad. After I did that though, I noticed when I start the truck all the gauges shoot up to their maximum, settle back down and then go to their normal positions. This never happened before. Could there have been a computer problem that after removing and reinstalling the fuses reset the settings or something? I still haven't changed the battery but yes it is under warranty. It starts slow but it's still hanging in there.
It is definitely a bad cell, 2.1V per cell = 12.6V -2.1= 10.5 It reads 14.6 when running because of the alternator service charge.
when u turn on your truck but don't start it that is the voltage in the battery. when you start your truck then it reads the voltage coming out of the alternator. it could be a bad cell or maybe just your alternator that is giving you these problems.
Ok, first things first. The person who responded with the explanation of the test you did is correct. Let’s get a little more information from you. Is the battery the correct application for the vehicle? How old is the battery? Has it been tested? If you remove your negative battery cable and set your meter to Ma (Milliamps) you can measure the drain from the truck on the battery. Make sure you shut everything off in the truck and have all doors closed. You should have less than 5Ma. If it is higher have someone get in the vehicle and remove fuses until the reading comes down. The fuse that brings the Ma down is the circuit with the fault and is draining your battery.
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