SR20DET wiring woes.

For the RWD SR20DET cars! Sponsored by Wiring Specialties.
Black&Blue
Posts: 2
Joined: Fri Feb 28, 2014 1:55 am
Car: '91 240sx LE

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I'll cut straight to the chase...

- Bought JDM 180sx front clip from importer
- Saw and heard it run on carb cleaner before loading it up
- Ripped it out as soon as I got it home
- Took out lower harness along with engine harness to be safe
- Modified SR engine harness following FRSport instructions
- Got lost following said (crappy) instructions
- Found sick video from Wiring Specialties
- Finished harness
- SR is now in 240sx
- No power anywhere
- After enough crunching I found out where everything goes
- Starter cranks now
- Fuel pump relay has constant power with ignition off
- Fuel pump relay loses power in the START position
- No power to fuel pump even with power to relay
- Grounds have been triple checked

What am I missing?


User avatar
Hijacker
Posts: 15759
Joined: Wed Aug 13, 2003 4:57 am
Car: '92 240sx Convertible
'94 F-150
Location: Fredericksburg, VA

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The relay should have a 12V supply with the ignition in 'on' and then grounds through the ECU. If you're getting 12V to the relay with the ignition in the off position, something sounds wrong with your ECU. All of the wiring for the fuel pump relay and the fuel pump itself should have been untouched by you. The only thing you should have messed with fuel pump wise in the wiring should have been the ground to ECU (black/pink). Everything else is contained in the chassis harness.

Black&Blue
Posts: 2
Joined: Fri Feb 28, 2014 1:55 am
Car: '91 240sx LE

Post

Hijacker wrote:The relay should have a 12V supply with the ignition in 'on' and then grounds through the ECU. If you're getting 12V to the relay with the ignition in the off position, something sounds wrong with your ECU. All of the wiring for the fuel pump relay and the fuel pump itself should have been untouched by you. The only thing you should have messed with fuel pump wise in the wiring should have been the ground to ECU (black/pink). Everything else is contained in the chassis harness.
Pretty much what I thought. Thanks for the reply although it's quite late. Ended up coughing up the cash for a Wiring Specialties harness because I couldn't figure it out. All I did was cut/extend and what I modified I followed exactly to what the Wiring Specialties video said.

The chassis harness on the 240 didn't help though. It's still a mess even though it runs now without problems using the premade harness. Whatever I messed up could have been something as simple as shielding but it was enough to keep me from wiring for a while.


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