I'm so lost. I was driving and the check engine light came on, when I looked down the speedo was going nuts. All electronics are pulsing (dash lights, blower motor, fuel pump etc.) I replaced the speed sensor/alternator fuse and it just blows after 5 seconds of engine running. Found my EXACT issue in the honda bulletin, linked below. I have the same 3 CEL codes and symptoms. A code for both o2 heater circuits, and for the ELD. It says the intake bracket rubs away the wires but I took the whole intake off and the wires look perfect. So I don't know what the problem is. o2 sensors look fine and the fuse still blows with the speed sensor unplugged. I had to put my old ecu in to get the codes because suddenly my p28 s300 is not sending data to my laptop, even though it connects. Did the short fry my $500 ecu?? I need tips on where to look now that I have the intake off. No symptoms show until the engine is actually running.

https://www.justanswer.com/uploads/l...fuse_blows.pdf

Car is a 1997 civic ex coupe, d16y8. Everything is stock except full exhaust with stock cat and an ebay adjustable fuel pressure regulator.

 

I experienced a similar problem on my '00 Si years ago... it turned out to be a bare spot on one of the yellow/black 12v+ wires at the junction block plug under the intake manifold. The bare wire was making contact with the block/water pipe... I repaired the wire by replacing the pin and the wire just beyond the damaged point and all was well.

 

I took the intake off so I could see the junction cables. They look fine but a lot of it is wrapped up in this square tube thing. Can't figure out how to open it but I'll try tomorrow. If there's a bare spot in their idk what it would be rubbing against to short out. Ugh my poor car...

 

It would help if you had an electrical schematic so as to see what is fed from the fuse
Then to go about looking for shorts in those circuits
Sometimes you can see a connector in line and taking those off will sometimes show where the short might be or not

Visual inspection is great if you can actually see the problem
Have you got a test light or DVOM?

 

I have both. Considering the problem is only with the engine running I'll follow more wires from the alternator, and I'll try to decipher these basic wiring schemes in the haynes manual. It can't be coincidence that I have the exact symptoms and codes from the honda repaie bulletin.

 

Disconnect the battery. Detach that branch of the harness from everything it connects to on the back of the engine and pull it back to where it branches near the starter. You can now make a full inspection and repairs.

Some of this is best done from underneath the car. You have to unclip the harness from the intake manifold bracket, that is where the problem is.

 

Had the same exact issue, I was able to do the repair in the parking garage at my office last year:





Had some leftover electrical tape that I used to cover up the frayed wires and wrapped the bracket as well to prevent the wires from rubbing again, which solved my issue. Good luck!

 

Frozti, check your PMs I sent you something that may help.

 

google fuse 15 tsb.

 

Welp, it's always the simple things. I thought this would be my first issue that wasn't user error. O2 wires were shorting on the heat shield for the cat, they were pushed against the shield because my China header is shorter than the original manifold. I briefly looked at the wires but not close enough. Wasn't a complete waste of time, while I had the intake off I wrapped the potentially problematic wires up and changed my pcv. Thanks for the replies, much appreciated.