Mechanics

CHARGING SYSTEM ISSUES

2003 Honda Civic • 4 cylinder 2WD Manual • 170,000 miles

The car is a 2003 Honda Civic SI 2.0 liter with 170,000 miles on it. The car is completely stock except for an aftermarket head unit (which has been running warm) and speakers. I do not have an amp or anything else attached to the electrical system. I was driving with music on and the charging system light came on, my speedo stopped working, and the electrical power steering light came on. Checked the voltage with a multimeter and it was approx 12.5 volts. The car has the original alternator and I replaced the battery 5 months ago. The fuse for the alternator was blown so I replaced that (i didn't have the multimeter with me when I replaced the fuse) and after driving approx 10 miles the fuse blew again. Where should I start to fix this? Could the old alternator cause a temporary short that blew the fuse? I had a CEL code for the electrical load detector-high voltage p1298 (which I replaced and the code didn't go away when cleared) and a faulty 02 sensor which I have not replaced. Any insight would be helpful.
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Bamp78
August 21, 2011.



Yes a bad alternator can blow that fuse with a good fuse have the alternator and battery tested also make sure the battery cables are clean and tight.

Saturntech9
Aug 21, 2011.
I took out the fuse for the head unit and replaced the 10amp fuse for the alternator with a 15 amp fuse and the car is charging at 14.6 volts while running. I drove the car for about 15 miles w/out any issues. Tomorrow I will put a 10amp fuse back in the alternator slot and see if it blows. As soon as the weather clears (i don't have a garage) I will be removing the head unit and checking the wiring there. The battery terminals were clean and the grounds running off the battery looked ok. The alternator grounds are in the support structure for the radiator and I have to remove the bumper to get to them. Thanks for the advice and I will post new info when I have it.

Tiny
Bamp78
Aug 21, 2011.
Alright never put a larger fuse then comes factory otherwise you could cause bigger problems fires further damage etc. Keep me posted on what you find.

Saturntech9
Aug 21, 2011.
Yea I hear what you are saying. The difference between 5 amps when the line is probably rated for higher is negligible for a day or two. If the line blows w/ the 10a I will thoroughly go through all the wires to see if there is an actual short. I am moving to a major city w/ good mass trans in a few months and just need the car to last until I get there. I do appreciate the feedback. While I can fix most mechanical things on a car it's the electrical work that I don't have a lot of knowledge about. I will post updates this week as I work on it.

Tiny
Bamp78
Aug 22, 2011.
Keep me posted on what you find.

Saturntech9
Aug 22, 2011.