RPMvulocity

car is a 98 honda civic sedan with a ls turbo

I had it running PERFECT one day, turned it off for the day and came back in the morning to a no start. Timing is ON, there is spark and fuel but car doesnt turn over. It jus stays cranking. So i checked my fuses and noticed that the Fuse 31 starter signal fuse is blown, i put a new fuse and as soon as i crank the engine it blows, then when i put a larger amp (for the purpose of seeing if it will turn on) it slowly cranks and hesistates almost in a pause. I dont have a wiring diagram and dont know where to find one online (i know there gotta be a place to download it or view it without buying a helms or ETM book from honda) i dont know where to start or what's before the fuse. If anyone can help me that would be greatly appreciated. thanks!

mouab18c1

iTrader: (5)

Check your ground wires

RPMvulocity

Grounds are good, I have four grounds in the engine bay and they're all good. So I finally got a wiring diagram that shows what fuse 31 is part of. So before the fuse it gets power from the ignition switch and starter. I check the signal wire for continuity all the way to the starter signal relay and it's good. The relay itself is good so I'm stumped. There should be a short somewhere before the fuse for it to blow a fuse correct? After the fuse it goes into the main relay but the main relay is switching on seems to be working fine. I don't know where to go from here and don't know exactly why the engine won't turn over

mouab18c1

iTrader: (5)

The engine wont turn over because the fuse is popping. Did you check your starter ground wire? along with your alternator ground wire?

Former User

The test:
Reinstall a 7.5A fuse into the dash fuse 31 slot. One at a time, unplug the integrated control unit (in dash fuse box), the main relay, or the ECU. Then crank the engine. Does unplugging one of these components prevent fuse 31 from blowing?

RPMvulocity

i will try that and let you know, thank you

Former User

It has not yet been said, but there is an electrical short somewhere downstream of fuse 31. As you can see from the diagram I posted, the short can be in a wire (Blu/Wht), the ICU/dash fuse box, main relay, or ECU. Determining whether unplugging one of the components downstream of fuse 31 prevents it from blowing will help to locate the source of the short.

RPMvulocity

where is the integrated control unit?

Former User

It plugs into the rear of the dash fuse box.

Start with the main relay and then the ECU.

RPMvulocity

thank you

Former User

The Blu/White wire pins to 31P ECU connector C (C6), so only this connector needs to be unplugged:

RPMvulocity

So...i took each component off like you said and it still it blows the fuse. when i took all main relay and ecu off it didnt break, but when i put it back it on, the fuse stopped breaking but the starter only clicks. i took the starter off and had it tested, it kicks on but doesnt turn real fast. the guy who tested said it seem to be fine, but i swear the starter kicks on hard and spins real fast. it sounds like a fan spining. So...im confuse

Former User

Sounds like your battery is low on charge or dead. Have it tested and charged/replaced if necessary. If the battery is fully charged, then check the large starter wire and its connection. Of course, the starter problem is separate from your fuse 31 problem. Once the starter/battery problem is solved, redo the tests. If disconnecting the three components does not prevent fuse 31 from blowing, then you have a short in the Blu/Wht wire leading to the main relay and/or ECU or the dash fuse box is bad. Do you have a multimeter to test for shorts?

RPMvulocity

yeah the battery is fully charged, that's what im using to check the circuit is a dvom, i'll check the blue/white wire

Former User

My troubleshooting strategy assumes that the circuit downstream of fuse 31 is stock and not modified. Is this correct?

RPMvulocity

from what i can tell it is

Former User

Remove fuse 31 and unplug the main relay and ECU connector C. Then test for continuity to body ground on the Blu/Wht wire.

RPMvulocity

blue/white wire at the relay or ecu? or fuse?

Former User

Testing the wire at the ECU or main relay plug should be fine.

RPMvulocity

hey wat's that green plug that comes from the engine harness, i was curious what the pin out is what goes in there

Former User

What green plug?

RPMvulocity

it comes off the engine harness i think...there's the plugs that go into the ecu and another that connects to a plug that comes from the chassis

Former User

Post pictures. What are you trying to do? Did you test for a short?

RPMvulocity

no not yet i havent done it yet im at work, bout to get off so i can do it...i jus remember seeing it yesterday and there was a plug there that looked kinda chop up

RPMvulocity

this green plug...i wanna know what's it for