Anothersmith

Hi guys,

As the title says I am having some issues with my main relay, I have looked for diagrams online but they all seem to say the wires are in different positions or different colours. Also a lot of them tell me what wire does what on the relay but not where the wire comes from - so hoping someone can help me from the pictures provided. Here goes.

The car turns over but the fuel pump doesnt run. Admittedly i do have to run a jumper cable from the battery to the starter motor to get it to turn over, but I will sort this issue out once I know the car runs.

Currently with my ignition on, number 5 (yellow red) has power and all other wires except number 8 (green) have a ground. Number 8 never shows anything, power or ground.

I sent power to number 1 (two black and white wires into one port) and the fuel pump primes but doesnt run constantly, so I know the relay works and it must be a wiring issue. On crank, all the wires stay as they are, with 5 getting power and all the others only getting a ground. When I send power directly to the fuel pump, it runs, so I know it works.

So, can anyone tell me what is going on here or point me in the direction of where to start with this?

Failing that can anyone tell me what the two white/ black wires are? As from diagrams I have seen they should be constant battery power, but on the car one goes off through the firewall and into the engine bay, and the other goes towards the ignition, maybe for the switch, but none get power. Does anyone know where these are supposed to go?

Or what the green wire should be doing (number 8 on the pin).

All help appreciated.

Cheers



Colours are as follows:
1. Black white
2. Black
3. Black / Yellow
4. N/A
5. Red / Yellow
6. Blue/White
7. Green / Yellow (fuel pump)
8. Green

Wire colours


Wire colours


Relay plug

Anothersmith

Bump

JRCivic1

What year and trim is the body ??? Most importantly, I see you have a OBD-1 style ECU and a jumper harness. Is your OE engine harness OBD-2A or OBD-2B style ??? Are all three ECU plugs side by side with no gap between any, or an open plug space between two of the three ECU plugs ??? Post this and I can get you a wiring pin out.

One more thing: I don't see any black/white wires in your photo. I expect you meant white/black wires as stated later in your original post. It is customary to refer to a multi-colored wire with the major color first and the stripe/trace wire second. In your pictures above, this would be a white wire with a black stripe/trace... or white/black. In addition, if you look closer, you will see one of the two white/black wires has a single silver band around it and the other white/black wire has a pair of silver bands positioned fairly close together. These are spaced along the wire's length every so often for identification. Referencing the wire color and including the bands in the description is even more specific... and can help you isolate the issue or get help even faster. For example, had you said "I don't have any power on the white with black trace and single silver band wire nor the white with black trace double silver band wire... where does this power come from ???"... you couldn't get any more specific than that.

Anothersmith

Thanks for the reply! the car is an EK from 1998 and the trim is LS (vtec). Not sure if you have that trim if you are from the USA but in the UK it is a d15 engine as standard. I believe it is OBD2-a as there is a plug then a space then two more plugs. That would be great, thanks for your help!

haha you are correct I did mean white/black. Hoping this little attempt into working out whats wrong will help me learn more about wiring so thanks for adding to my education

JRCivic1

I can only offer you USDM wiring charts because that is where I am located and I only have USDM factory service manuals. So, my disclaimer here is that you use this information at your own risk because I am not certain that it is identical to your market.

I am going to use the wiring scheme for a 1998 USDM Civic EX which has the 1.6L Vtec engine in it and has OBD-2A style ECU plugs.

Pin locations are numbered from left to right when looking at the brown FI relay plug from the wire side of the plug and the lock facing up. Top row first, then the bottom row.

Top row: 1,2,lock clip, 3
Bottom row: 4,5,6,7

7) white/black -> 10A FI/ECU fuse in the under hood box.
5) yellow/green (yellow/red in your photos) -> 15A fuel pump fuse at position 13 in the under dash fuse box.
6) yellow/black -> to a junction connector and ultimately back to A24 at ECU
2) blue/white -> 7.5A starter signal fuse at position 31 in the under dash fuse box.
1) green/yellow -> A16 at ECU
4) yellow/green -> to fuel pump
3) black -> through a junction connector and ultimately back to A10 at ECU. This wire is also joined to the black wire at A23 at the ECU.

I hope this helps. Good luck.

Anothersmith