Hi all, I was referred here by a user at honda-tech.com, so I'll just copy and paste my question and follow ups here, hopefully y'all can help me

Yesterday I installed a new head unit, amp, and sub in the civic. Nothing I haven't done a hundred times before. (I did blow a 7.5A fuse, but replaced it and everything seemed to work fine again.)

I went to start the car after I was done and it won't crank. All dash lights come on, HVAC powers up full strength, but I get nothing when I turn the key, not even a click. I used an external 12v trickle charger to make sure it wasn't the battery, and I'm still getting the same problem. I pulled and checked all the fuses under the dash and in the engine compartment, no luck there.

Any ideas?

UPDATE: I push started the civic and it started right up. Drove up and down the highway until the IMA battery was 3/4 charged or so, then came home. Tried starting the car immediately after shutting it off, and nothing. Same problem.

The clutch is fully depressed, maybe I jiggled loose a clutch sensor wire in there somewhere?

UPDATE 2: I've only owned the car for a few months. It was seemingly well taken care of, but I don't have any service history. The battery up until this point has seemed strong. I've push started and driven it twice now, hoping to charge the 12v battery, and I also trickle charged it for 3 hours, and I still don't even get a click when trying to start it.

Weird thing is, when I drive it, the auto-stop works fine, shutting off the engine when coasting and at stoplights, and then restarting when I shift into gear. So the electric starter seems to work fine...

One more thing: The airbag lights comes on and stays on as I drive.

 

No idea. Wish I could help.

 

There is a clutch interlock switch located up at the top of the clutch pedal. You can pull the connector and test the switch. (You should measure a short between the two conductors when the clutch pedal is pressed.)

If you get the HCH shop manual there is a long series of tests to follow for diagnosing the "will not start" problem.

You said you blew a fuse, which one?

There is also the possibility that some of the electronics you installed are actively screwing something up, for instance shorting wires or pushing a voltage onto something that should be grounded. If you unplug it all, will the car start?

On my 2003 there is a security code that must be entered into the radio to make the radio work. I wonder if they might not have extended that for the 2005 to the extent that the car will not start without the security code. There doesn't seem to be anything in the shop manual about the radio, and in any case, the one I have is only for 2003/2004.

One other long shot - disconnect the battery, wait a minute, and reconnect it. With no battery minder. Just in case somewhere or other the car has stored some state information which is confusing it. Honestly, the odds of this working are maybe 1 in 1000, but hey, it is easy enough to do.

 

 

Probably a different issue to the OPs then, if you haven't installed a radio then your problem is just that the car won't start, which could be any number of things.