After leaving my 98 Civic DX parked for about 30 minutes today, i got back in, turned the key, and the spedo never registered. also, the lights started dimming and brightening rhythmically with the motor lightly revving (bouncing between ~1k and ~1100). this is also abnormally high for my idle, which is usually around 600-700. i have a decent bit of stereo work, as well as some light modifications. I plan on having the alternator tested tomorrow, and if its shot, I'll be giving Ohio Generator a call, but is there anything else i should be looking for? Thanks in advance.

mods:

audio/electrical
JL Slash v2 500x1
JL Slash v2 450x4
JL 10w7
JL XR650-CXi (6.5" 75w RMS)
MB Quart RVF 210 (4" 75w RMS)
Eclipse 5100

motor
generic intake, 4-2-1, cat-delete, and cat-back exhaust
Blox intake mani

 

sounds like a ground problem

 

which ground would it be? any other grounding problems I've dealt with have been sporadic, and this is solid and rhythmic. I did just have a security camera removed though, so i might want to check those wires...thanks for the idea, I'll check all the wiring tomorrow as well. Any other recommendations?

 

Is fuse 15 blown? Is the CEL ON? If so, retrieve the CEL codes and read this:

http://www.tegger.com/hondafaq/tsb/civic/x99-029e.pdf

 

the CEL is always on; as i said, I'm running a cat-delete, so the secondary O2 sensor pops it. I'll run a scanner in the morning and see if any new codes are stored. My in-car fuse cover is...gone, so I'll have to figure out which is #15. edit ignore that, found a diagram. Sometimes Google is my best friend.

in regards to that bulletin, that could very possibly be the problem. when swapping the intake mani, i removed the "bitch bracket" because it served no real purpose, so the harness wouldn't be rubbing it...but it might have found something else to rub. I'll pull the mani and give it a look when the sun's out. thanks!

 

Decided to pull out a flashlight and check the fuse...yep, #15 is blown. so, when the sun is out, I guess I'll be pulling my mani tomorrow to figure out what the wire harness is grounding on. Thanks again.

 

FYI
If you raise the front end on stands, you may get access to the wire harness from below the car without removing the intake manifold. The wire harness is just above and to the right of the oil filter.

 

Yeah it's much easier to work on that problem from underneath. Fuse 15 feeds the O2 sensors, so if the wiring for your dis-used sensor has found a ground it'll blow the fuse. Also I'm pretty sure Honda put that bracket there for some reason other than to wear out the wiring harness. You may be risking a cracked manifold running without it.

 

finally got under the hood. here's what I've got

MIL DTC17 (vehicle speed sensor) is lit, as well as DTC 41 (primary O2). I expected 41, because of the cat-delete.

fuse 15 is blown. replaced it, and it immediately blew again. For spits and giggles, tried to replace it a second time. once again, blew as soon as i turned the key.

so far, I have all the symptoms listed in the SB you posted, RonJ. I went under the IM to find that harness, and instead found two separate connections. here are some pictures.

http://www.imagedump.us/uploads/5faf14dfa8.jpg

http://www.imagedump.us/uploads/65d1f91621.jpg

The SB shows C115 as having wires coming in both sides, but both of those connectors do not. I pulled the caps from both connectors, and there was no burning. what am I missing? I'm tempted to take this to the dealer tomorrow, but I'm not trying to pay out the *** for something I can fix myself.

 

I recently hit a speed bump that took out my secondary O2 sensor...bent it all to hell. After reading what you mentioned, I'm gonna try lifting the car and seeing if maybe the wires for the secondary have found a ground on the metal housing for the O2 sensor.

The Blox IM did not have a spot for the bracket to bolt to, so when i swapped the mani, it became superfluous. Good point though.