FIXED: Random Power Off and Engine Shutdown?
 

When driving the car, the engine and power will all sporadically shut off like as if I disconnected the battery and turned the key off at the same time. Everything turns off all at once. Sometimes it's rapid where everything shuts off and then turns back on and then shuts off and then turns back on in quick succession. Other times it will completely shut off for several seconds before power comes back and I'm able to start the car. This is all regardless of if I'm parked in the driveway, driving in the neighborhood, or driving down the freeway.

This issue was really bad a few years ago and I took the car to four different places before it was fixed. They replaced the alternator, the battery, one of them said it needed some new wire, and then another said I had a short. The problem was that the issue is/was completely random and I do not have a solid way to replicate it. Because of this I would have to assume the repair fixed it each time and then it would randomly start doing it again. It eventually got better and would only briefly (rarely) do it once every few months. Today it was really bad again like how it used to be.

It's pretty terrifying because sometimes it happens in the middle of an intersection or on the freeway when I'm completely surrounded by other vehicles. Or at night and the lights all shut down and I can't see anything. Today I was able to get it to do it almost on command. It seems that whenever the car is running "normally", if I turn on or off anything that involves electricity the car reacts to it by having the problem. More specifically: While driving, If I turn off the A/C the EPS light will briefly turn on and the dash will flicker. While driving, if I turn on the brights (the regular lights were already on), the car will continually turn off completely (electrical and engine) and turn back on even after turning the brights off, until I take my foot off the gas and put the car in neutral. After doing each of these two things over and over, eventually it will stop reacting to one of them (almost like it remembers how to handle the issue) but then if I randomly do something else power-related it acts like it forgot how to handle the new thing and has issues again (and then forgets about something else).

Another thing I noticed is that it resets my CEL whenever it starts acting up. My CEL is on due to EVAP leak (as far as I know; is it possible for a CEL code to mask another code if there is more than one issue?) and my Maintenance required light is on because I change my own oil and lazily don't reset it (which is going to change very soon now that I'm trying to fix everything wrong with the car). I found it strange that it clears the CEL but not the maintenance required light (although it is strange that it clears any of them). Another interesting thing to note is that the ABS and EPS lights both turn on when the power comes back on.

Here are some videos I was able to capture when flicking the brights (please excuse the dust, I just vacuumed out the car and it started raining and I wasn't able to finish cleaning the interior). It is worth noting that it doesn't look quite the same on video as it does in person. In person, the whole dash does a full blink and everything is off, I'm assuming the video frame-rate doesn't keep up with it. Additionally the headlights shut off too when everything shuts down:

The car does not have any electrical modifications that I am aware of. The only real modifications to the car are the exhaust and the air box mod (which isn't relevant to this because it's been the same before and after). It is worth noting that it is right around 188k miles on the odometer.

I tried searching around but I couldn't find any posts that had this exact specific issue, sorry if I did not search hard enough. Hopefully I provided enough detail, I'm really stumped on this one. If you need more details please let me know, I can provide any pictures/videos necessary.

Oh, I just remembered. The previous owner had some fog lights that they installed. They were broken when I bought the car and were completely removed. I don't see anything that it would have tapped into that would cause any damage, but I figured it was worth noting. I looked over all the wiring from where it was and it just connected straight to the battery and they had a switch in the driver's footwell but it wasn't tapped into anything from what I remember. It was removed a long time ago and doesn't seem to be what is causing the issue to come back but I could be wrong.

Maybe, a bad grounding point(s)? I'd check those, first.

Good luck! :)

The major grounds are always suspect 1 in this sort of issue. Make sure that your battery isn't grounding out on the frame or hood. Trace the negative battery wire to the firewall, and ensure that the connection is clean and tight. Take it off and sand it if needed. Probably most importantly, ensure that the ground on the back of the engine block is tight. These connection points are relatively easy to locate and free for you to clean and tighten. Start with the simple fixes first.

Additionally, you might just have a bad alternator, rectifier, or battery, which is causing the voltage to drop when there's a power draw.

Check also battery connections, alternator connections and main fuse box under the hood. Look for melted plastic around big fuses nr. 24 and 25. Because loose connection generates heat.

+1 on cleaning all grounds. Whatever grounds you clean, clean both the terminal, and the spot on frame or whatever it boots to with a scuff pad, then apply some grease to prevent future corrosion. Some like to use dielectric grease (non conductive grease), but for grounds, I prefer regular grease. The more conductive the better. Something like copper antiseize would be good.

#2 is the ignition key switch. If it were going bad, it would be like you turned off the key. All power gone. Next time everything is dead, try to use something electrical that isn't keyed off the ignition. Like the horn. See if horn will beep when everything else is dead.

If it does, I'm betting its a bad ignition switch. Do you have a lot of heavy stuff on your key chain? Maybe the PO did. All tbat weight can cause it to go bad. At this point, it may be worth replacing ignition switch just to rule it out.

The key part stays the same, so same key. Its only the electrical part of ignition that gets replaced. I bet you could find a diy on how to do it.

Thank you for all the responses. Once it stops raining I'll go ahead and check and clean all the grounds (I don't have any grease at the moment but I'll go ahead and order some and grease them once it comes in). The battery does not have anything covering the connectors (it never has), but it doesn't look like it is grounding on the hood. I'll be sure to cover the connectors just to 1) be safe and 2) rule that out.

I did the "wiggle test" on the ignition to see if I could get it to shut off or do anything weird. I saw a bunch of videos and posts mention to do so. I realize that doesn't completely rule it out, but just figured I would throw it out there. As for my keys, it's pretty standard, not heavy.

While moving the car I heard something that sounded like fluid trapped somewhere shaking around. It may have been the gas tank(?), but I've had roof leaks before and want to be completely sure. And if it were the gas tank I think I would have heard that sound before, right? Anyway, I went ahead and took out almost all of the interior plastic surrounding the seats and soft top and I think I'll have a solid answer on that pretty soon. I just checked and saw a little bit of dripping coming from the soft top lining behind the seat. I'm not sure if that is the main leak or not, but I'll add it to the list of things to fix. I also disconnected the defroster; I wanted to rule it out since it was installed as well. While pulling off one of the window connectors, one of the connection pads came off (looks like it was a poor connection) so I'm going to have to re-solder that as well but no big deal :argh:.

I'll keep you guys updated.

I went on a drive today and it was having the same issue. When I parked it, all the power cut out (I only noticed because the car wasn't locking with the key fob). I got back in the car and tried to start it and there was no power at all. I popped the hood and messed with the battery terminals a bit and all of a sudden power was back. The drive back home there were no issues at all. With that said, I think the battery terminals might be messed up. If that is the case, it sort of makes sense that the issue has come back after all these years since I just replaced the battery 2 weeks ago (it's OEM (Interstate) and very healthy so I knew the battery itself was not the issue. Before the drive I double-checked the grounds and everything appears good in that regard. I'll go ahead and replace the battery terminals and report back with how it goes (whether or not the issue is fixed).

Buy a new battery ground cable. They aren't expensive, even new from Honda. Lots of users report that they get corrosion up inside the middle of that cable, and it wrecks their #$@ for YEARS because they're unable to track down the problem. The cable looks just fine externally, and unless you strip the cover off, you'll never see it. If you believe that the battery has something to do with it, I'd focus on that negative cable and attachment to the firewall.

I replaced the battery terminals and have been driving the car the past few days. The car has not had any issues regarding this problem since I put on the new terminals. I'll post in update if the problem comes back, but I think for now I can say that the issue was with the battery terminals.