My Civic is blowing battery fuses, help?

[chad]

Let me start by saying I drive a 2004 Honda Civic LX. So last week, I changed the head gasket on my car, and this week, after I put everything back together, I noticed my headlights were flickering (not bad, it was subtle.) So I checked the ground to the battery, and like a moron (It was late, I was tired,) I checked the positive post on the alternator, forgetting to disconnect the battery first. I’m betting you guys can guess where this goes, yep, I touched the frame with the wrench and I got a spark. Afterwards, I looked in the fuse box and saw that the battery fuse was blown. I disconnected the battery and went to finish what i was doing and the alternator post snapped off (it’s right next to the exhaust, car had overheating problems prior, ergo…) I ended up getting an old alternator identical to the one I damaged and installed it yesterday. After that, I put in a new fuse, and went to reconnect the battery and the fuse blew again, and the positive terminal began melting the post.
Now, I’m not an electrician, but I poked around a few forums where other people have had a similar problem, and I’m coming up short, so I’m asking ya’ll for help. A few things I know for sure: the ground from the engine block to the frame is good, the ground from the harness to the engine is good, the fuses for the ignition and alternator in the drivers seat area are good, and the negative ground from the battery onto the frame and to the transmission is good. I put everything from the wiring harness back the way it came off, The battery is connected in the right way, and if I disconnect the alternator, and put a screwdriver between the broken fuse link for the battery (80 amps btw,) and turn the key, the car starts. I’m thinking maybe I damaged one of the wires in the harness somewhere, because there’s some white stuff that looks like paint where the positive cable from the battery touches the fuse box (One of said cables leads to the alternator,) could that be some type of corrosion? It’s difficult for me to tell what wires may be damaged because they’re all wrapped in a thick black heat shield. If I have to replace the harness, then that’s what I have to do, but can you guys tell me where to look next?

Topic

[Mike]

[quote=”Hondadude” post=172513]…and the positive terminal began melting the post.[/quote]

Sounds to me like your positive cable is shorting directly to ground.

[chad]

If so, how do I remedy it? Replace the positive cable? Again, not very electrically inclined.

[Mike]

For starters, safety first. Keep the battery disconnected. This type of thing could be a fire hazard, battery explosion hazard, and a shock hazard.

Do a good visual inspection of the positive cable. Remove it completely from the engine compartment if you can. You’re looking for burn marks, broken insulation and exposed wire, swollen insulation, anything along those lines. The cable should be flexible along its entire length. Any area that feels like a gritty hinge or bends with no resistance points to internal failure.

[Paul Hartmann]

if your car would run, you could do a voltage drop test on the pos. cable. google “voltage drop” to read how. I agree with the first poster: replace the pos. cable. if that fixes it, do a voltage drop on the ground cable.

[Rob]

first off do a visual insprection to see if you see anything
leave the battory out and do a conitity test… across the battory post leads that are on the car… see if it shows a short.. replace the blown fuse and try it again if it says short you can remove one at a time or just jump and right what each one is and pull out all the fuses and relay and check it again it shouldnt show a short put one by one in at a time and keep rechecking it to see if it shows a short
when you see it and figure out wich one it is what fuse you will have to trace it back and see what it runs and check the cables.. try disconnecting each of the cables in that line from the secor’s or parts… basiclly doing one at a time
will take you some time but you will figure it out

[Dave]

Reading your post, I am going to assume that it is possible that when you put the engine back together that you possibly pinched a wire or so behind a bracket, a valve cover, or something you had taken loose. I would check everywhere you had worked for any wires being pinched. This will take a flashlight and a lot of effort.
Do as others suggest, pull all the fuses and slowly installing them until one blows. That is the circuit that is shorted out to ground. Or, if your main fuse blows before you can even get that far. You will need to do an even better visible search for shorted out wires. Check the loom the headlights are on. They gave you a pretty indication that you were getting a short before everything died.
Do not get frustrated regardless. Just take your time and look really good. Once you find the issue (DO NOT USE ELECTRICAL TAPE TO FIX IT) This is the worse thing you can do. Though it may last a little while, it may cause a lot of issues in the future. Use a splice that has shrink tubing on it. Splice it really tight, then heat up the tubing to shrink it around it. Then use some electrical tape (quality stuff) to add extra protection and if possible corrugated wire protectors to further protect it. It should last you a long long time. Make all the wires that were pinched get spliced back together correctly.
You want again quality splices. Some have solder in them and will actually help fuse the wiring together. Happy hunting.

[Author]

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