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Q: 25 amp fuse blows after it's charged

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The 25 amp fuse sitting on the positive lead that comes out from the rectifier, instantly blows after it is changed. This causes the battery not to charge when the motor is running. For the fuse to blow, the engine doesn’t have to be running. I decided that there is probably something wrong between the fuse and the battery. At one time, I found that the battery had been connected with the positive pole to grounding and the negative pole was where the positive should have been. After that, the main fuse blew and it was replaced. I’ve tried replacing the battery, but that didn’t help. What should I do to fix this and do you have a wiring diagram or know where I can get one?

When the battery was hooked up incorrectly, something must have been fried in the computer or other wires. You can find wiring diagrams in service manuals that are dedicated to your specific vehicle such as Chilton, Haynes, or factory specific manuals. You may also be able to find wiring diagrams on the internet but be careful with those as they may be incorrect.

I would recommend having this issue diagnosed by a professional who is proficient in electronics diagnosis. This will save a tremendous amount of time when getting down to the bottom of this issue. Taking this route should not even cost too much extra than fixing it yourself as it will likely take the mechanic an hour or two to find out what is wrong, whereas you could spend a day or two figuring out the same issue. Once the cause of the issue has been found, the mechanic can then replace parts as necessary to resolve the issues you are having.

If you feel like you need assistance with this, get some help from a professional mechanic who can diagnose your electrical issue firsthand. Once this is done, the appropriate repairs can be made to get your car running normally again.

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