Did a really stoopid thing today. Was in a rush to hook a new battery into my 2004 Honda Accord, but in my haste, I put it in backwards(!) The only good thing i can say is, I did not try to turn the car on until I realized my error. But obviously, no power in car now. Checked all the fuses and as far as i can see, the only one which blew was the 100 volt battery fuse. All the others are fine. There was no smoke at any time. I'm assuming the new battery I got is shot, but do you think I dodged a bullet here by the battery fuse going out?

 

The 100A main fuse did its job to protect the electrical circuits in the car. Its hard to say if anything got damaged before the fuse blew. Have you replaced the fuse and tried to start the car yet?

The battery may still be fine, since the main fuse pretty much opened the circuit when it blew. It would be roughly like touching the two ends of jumper cables together when the other ends are attached to the battery.

 

No. Honda dealership was closed today & I will be out of town for the next few weeks. So I won't know until I get back. I think I will get a new battery just to be on the safe side. Thats the least of my worries. Would not be surprised if there was some more damage. Just wondering if it will be major or minor. if I luck out, I think I'm gonna get a tattoo of that 100A fuse!

 

You will only find out when the 100amp fuse is replaced. You will have to see if the other electrical components in your car are working properly.

If some system isn't working, then check the fuse first. If the fuse keeps blowing, then you are going to have some electrical troubleshooting to do.

As for a replacement battery, that is your call. You may want to get the battery tested first. If it tests ok, then you don't need to waste money on a new one.

 

There's a good chance that the fuse blew before damaging the battery. Get it checked out before buying a new one.

 

Yeah, Fuse first! .......Then worry about the next step. You SHOULD be fine.

 

Well, replaced the 100amp fuse today. Battery was ok, all the electronics seemed ok. Then I turned the key. It turns over but does not start. I heard the fuel pump buzz so I know that is ok. .Fuel pump fuse is ok too. So I'm assuming there is probably something wrong with MAF sensor or ECU.

Any diagnosis on this would be helpful. Also about what it would cost to fix. At this point I just want to lick my wounds, fix it asap & move on.

 

This has to be something small & stupid. There are too many safeguards in place for this to be a major issue.

Recheck all fuses and fuse boxes, fuseable links, etc. Try to pull codes, make sure ignition circuits are powered. There's gotta be something you missed!

 

First thing I would do is connect a scan tool to it. This will tell you if the ECM is alive and if it is, you can see if there are any codes. If you don't have access to a scan tool, since your fuel pump is running, I would check for spark. If you have spark, that leads me back to the ECM...