Yesterday I tried to replace (this is what used to be a simple job) a battery. Took the old one out, put in the new one and now the engine won't turn over. Horn works, headlights work and of note, they don't even dim when trying to start the car. I checked the battery and it has a full charge. I tried starting it in both park and neutral, still nothing. I tried jumping it with a portable power battery with no success. Is there some kind of a reset button you have to hit when replacing a battery or maybe a fuse that controls this? This car belongs to a friend and I'm really not that familiar with a Honda, although I didn't think I needed to be to replace a battery. Anyone got any ideas?

 

If thats the only thing you changed then it sounds like the ecu did not properly reset or its fuse is blown. Does it at least crank or is there no response from the ignition at all?

 

not dimming when starting is most likely the starter motor is not drawing current so most likely a starter problem.

but you need to check the s terminal wire for power when you turn the key to start position. if you dont have this 12v to the s terminal, then you need to get a wiring diaghram in order to trace the problem... could be bad switch, clutch switch, bad park neutral switch, blown starter fuse. etc.