Did I blow up my ECU?

[Deadrodent]

Hey everyone, I was taking my 240 for a little late saturday night cruise when things went horribly wrong. I had previously installed an autometer boost gauge and wired it to the car's ignition wire.

I took off the gauge because it wasn't sealing properly and was causing a vaccuum leak but i kept the gauge's light wired up. I had wrapped the gauge light around the steering column so it wouldn't be hanging anywhere or get caught on anything. While i was driving the gauge light was bothering my vision so i grabbed it with my hand and attempted to point it in a different direction. Upon doing this sparks flew from the gauge light (where the wires connect to it) and puffs of smoke came from somewhere near the steering column (i'm assuming where i soldered it)

the car immediately died but the lights and everything else work. When i slowed to a stop i tried cranking the car but there was no response. The starter didn't crank, my fans didn't come on...it's like the ignition switch was busted. I had an extra one laying one and replaced it...same problems....so my question is...could i have shorted out my ecu? Or seriously damaged my wiring harness?

[SpeedRacer1]

Its most likely not the ECU, the engine can turn over even without the ECU. You fried something in the dash wiring most likely.

[IanS]

check your fuses and relays

[joshcereal]

its your 75a fuse the big black one with the clear top in your engine fuse box just take it out and go to the part store or nissan dealership and get a new one

[Deadrodent]

k i checked all my fuses with a multimeter and they all conduct. i'm not sure how to check relays or what relays to check.

here's what i've managed to figure out.

- headlights and interior lights work.

- power door locks work

- i can not put the car in "accessory" or "on" so i can't roll up my windows

- the car does not even try to crank...

can someone please help me out? my car was running incredibly strong and i just fixed it....

[Deadrodent]

Bump! I need help!!!

Do our starters have a fusable link? i need to get my car up and running!

Does anyone know of 240sx/sr20 specific shops around the bay area that provide electronic troubleshooting? i'm willing to pay a professional to clean up my wiring and solve my problems

[CMG]

If you actually saw smoke coming under the dash you probably fried some of the wiring, it burns like a fuse sometimes when overloaded.

[Deadrodent]

so how would i go about testing or finding the problem?

[CMG]

start by looking around the area where you saw the smoke

[Deadrodent]

it was kinda hard to tell where the smoke came from....it came from around the rotary switch that connects to the back of the ignition cylinder...it also could have come from where i soldered my fan and boost gauge on the accessory wire except i replaced the rotary switch (which means the soldered connections wouldn't be there anymore) and it's still dead

is there a step by step routine i could use to narrow down what could be damaged? i need a little more help then this niconauts!!!

[jdm_master_X]

check for shorted wires. typically the insulation should be melted. or looks for arcing spots on metal parts. that should give you an idea.

[Deadrodent]

i'm really asking how to test the wires and which wires i should be testing....

i replaced the harness that runs to the ignition cylinder and it still doesn't work and all the little wires that run to the turn signals and such look fine