Hi there,

First post here, but longtime lurker so thanks firstly for all the invaluable advice.

I am having a pretty serious electrical issue and am looking for guidance. Right now I have an intermittent problem where sometimes while driving power cuts completely out and the engine dies. I've done a full charging system diag; battery and alternator/voltage regulator are fine as far as I can tell. I have had issues with the factory head unit/climate control for quite a while now which led me to replace the factory radio with junkyard factory radio for climate control and a cheap little cd player for music. I've also replaced the beefy transistor under the passenger side dash.

After doing all the described stuff above the radio and climate control worked for a while, but about a week ago the time display started flashing on the factory head unit. I went to start the car one morning and it was totally dead. I thought it was the battery so I jumped it and got it running no problem. It was at this point that the internal lights, including the dash lights, got a little funny and started cutting out. I also noticed when I wiggle the key there is some kind effect with the cutting in and out of the dash lights/ the intermittent starting problem. The blower is now blowing regardless of control setting and I have no idea where to start. Right now I plan to do a basic scan with a meter for all fuses related to ignition and climate. I've had cars with ignition switch problems, but is there any way to diagnose this with a meter? also is there a way to diagnose related relays without sending power to them (e.g. power probe/power supply).

Sorry if this is a bit rambley just want to be clear with what I've tried and what I know so far.

Thanks in advanced!!!

 

Since you can make the dash lights flicker by wiggling the key, that already points to a flaky ignition switch.

 

Not sure if this is the way to reply, but do you have a reliable way of testing the switch? I would imagine there is some kind of antiteft I’m going to run into. I’ll look up the service manual and see if I can’t figure it out somehow. Will update.

 

Wiggle the key to see if that causes the problem (you've already done that).

The one time I saw this in person, I was helping a friend with a 2000 Civic...
After removing the plastic covers from the steering column, I could see that the electrical part of the ignition switch was loose. It was not only coming loose from the mechanical key/cylinder part, but the action of the electrical switches was sloppy. If you don't see those kind of obvious things, then you would use a multi-meter to check if the switching action is reliable. I imagine if the contacts are dirty or burned, you would see unreliable continuity across the switch, or maybe the switch wouldn't make contact until the key is turned just a bit past the proper point, or anything like that.

The big anti-theft thing is the immobilizer. There's an antenna ring located close behind the plate where you insert the key. That reads a chip in the key, and the car's computer has to recognize the chip's serial# as one of the "authorized" keys before the computer allows the car to start. So that stuff is not likely to be messed up by taking the plastic covers off, but you also won't be able to bypass that stuff if you don't have the key.

 

I had this exact problem with my 07 accord. This gave me a reason to upgrade my battery. Once I changed out the battery to the 6 cyl size and the bigger ground cable it all was fixed. I also sanded down the chassis mount point for the ground to battery. Not sure what actually fixed the issue but you can try sanding then replacing the ground cable since the battery side loses its integrity over time.

 

thank you for the replies! I'm pretty busy but have been reading the FSMs and looking into your suggestions so I can tackle the work in a timely manner when I have a moment. the battery theory is interesting, but I have a fairly new battery and the contacts look alright. Ill trace the cables to confirm. Thanks, and I'll be back soon!

 

Connections at the other end of each battery cable - that's always a good place to check for corrosion, loose, dirty, or whatever. It's one of those things that people take for granted & don't check until after they've thrown a lot of parts at it.

But if that was the only problem, you wouldn't be able to cause the problem by wiggling the key.

 

my thoughts exactly. I'm also not 100 percent sure that its the ignition as the first time around, swapping the transistor fixed everything for a while. I will investigate. It is my goal to trouble shoot down to one or two reasonable fixes. Think I have it in me if I have the time.

 

poked around a bit, and cant get the ignition switch to fault anymore. instead, in between run and start I hear a bit of an electrical noise. Could be a short/ arcing? however if i press the key thru this spot she starts up no problem. The entire time, however the blower is going full blast regardless of settings. All of the other climate/radio functions appear to be working. Cleaned the battery terminals and checked ground, I think all that is fine. looks like some of the fuses under the driver side have some discoloration/minor burning on all the fuses I checked related to climate and radio. None of them are blown however so I am a bit stumped . I'm going to check out the blower transistor again, but all that I can figure is that if that blew again its getting too much voltage thru the emmiter/collector circuit and is blowing due to a system fault not due to any fault of the transistor or base(switching) contact. the transistor may indeed be bad again, but by swapping it I don't think this will fix the fault.

I'm thinking of detaching the aftermarket radio and hooking up the oem harness back to the factory radio and seeing if I get control back. not sure if that would cause an issue or not seeing as I was having a similar issue back when i decided to install an aftermarket radio.

Grasping at straws here...

Any other ideas? I'm thumbing thru the factory manual again, but at 7000 pages its a bit difficult to locate specific component locations.

 

If you had the same problem before installing the aftermarket radio, then the radio may not be the problem. It is worth a shot.

Is the blower motor always staying on the high speed setting even when the car is started?

Do you have any other aftermarket items installed on your car?