Have you changed your exhaust lately? It might be the wires from the o2 sensor grounding out on the exhaust or chassis. I was doing some work on an NSX and was about to order a whole new harness when I found that bull****. Car would blow the fuse right at "ON" before even starting the car.

 

Usually that blows the #8 fuse in the underhood panel but thats another good place to check. Been there myself

 

i forgot to add that my engine harness was also "semi" wire tucked and shortened soo yea.. just seems weird car started right up and ran for a good week with no problems after all the modifications were done to the car then as soon as i close my hood the car shuts off and blows that fuse.. but def sounds like a short somewhere

 

the whole motor was out so exhaust was kin of just hanging in there for a while

which o2 sensor were you referring to? the one on the o2 housing or the one on the test pipe/ cat?

 

Dude it is a short and it is the wire tuck they did, take it back to that shmuck who did the wire tuck and drop kick em in the throat.....

 

havent had a chance to mess with the car since temps dropped to low 20s and we had lots of rain the days before

 

Gotta agree here.

 

i should have a better later today when i get out of work and get to work on the car

 

WOW.. so i ended up taking everything apart to try n find it.. i wasted like 15a fuses already testing this issue.. so far i found out that if i disconnect one of the connectors that go to the fuse box, the fuse wont blow but im not sure which end of the connector to test to see which end has the short.. ill take a pic of the connector when i can

i was thinking of testing each pin one at a time to narrow it down and figure out what pin is shorting and then maybe looking up what pin that is for

 

when i disconnect this harness the 10a fuse wont blow

 

which side should i start to trace and find issue?..

 

since the short is gone after that harness is unplugged it's fairly safe to say the wiring to the fuse box is ok. start with #1 and doing a ground continuity check with the wires.

 

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Heres a quick pic of the IGN ckt diagram to fuse 1. I sent it to ya via e-mail as well so you can blow it up to see the stuff better.

Going by the diagram the connector you are looking at is A-29 and the coil power is pin 4 of that connector.

 

may sound dumb but how do i do a ground continuity check on the wires?

 

The ignition system uses ground #4 and #11. Ground #4 is on the driverside shock tower (neg battery cable bolt) and #11 is on the engine around the T-stat area. (all the same harness though)

You want to disconnect the battery first because having it connected can mess with your ohm readings.

I usually just set the meter to the "beep" setting on ohms, then connect one end to the ground cable. Touch the other probe to the pins in the connector of the suspect ckt to see if they do in fact have continuity to ground. (meter will beep, or you will get an ohm reading)

Then you start removing components from the system untill you narrow down the short by unplugging them. Easy in this ckt because all you have in it is the two coilpacks and the ecm, that should lead you in the direction of the short.