Keizer

I have a '99 Civic European version. The car suddenly won't start. I'm not getting the CEL light, either the immobilizer in the dash. I've been trying to measure the voltages like posted in this thread and all seems fine except I can't measure 12V on both tabs of the backup fuse. I get around 12.6 on one, and 1.7 on the other. I recently discovered, that the backup fuse was dead, I believe it has been like that for quite some time. I replaced it, but the car has been working properly without it also?

So the question is, is the voltages on the tabs ok? And does it affect the ECU, if no backup fuse?

Former User

Your voltage readings of the Back Up fuse indicated that it was blown. After you replaced the fuse, do you now read the same battery voltage on both tabs after driving the car?

The Back Up fuse supplies constant voltage to the ECU and allows the ECU to store CEL codes and sensor inputs (memory). If the Back Up fuse is blown, your engine won't run optimally, and also cannot store CEL codes so you won't know if the ECU is sensing problems.

Keizer

First thanks for quick answer.

I discovered the problem when I went through all the fuses in an attempt to get the car to work again. The previous owner had connected the radio with constant voltage either because he wanted it that way or he wasn't aware of the blown fuse. So I was quite happy when I could fix this problem and get the stereo working properly.

I haven't read out any voltages before I discovered the blown fuse, but replaced it as soon as I discovered it. Before all of these problems the car ran very well, quick and a good response.

It has to be said I cleaned up the engine compartment, but was able to start the car afterwards and park it (2 minutes max). Also the were this blinking LED at the drivers side. I disconnected it, because it looked like a quick DIY fix. I have reconnected it again and it's blinking. Although it's blinking in another order, which I think might have something to do with the problem i'm now having?

Former User

Picture/video of LED?

Keizer

I will upload a video or pic later. All i can tell is that the LED is connected to a white thick wire underneath the steering wheel and the other end is connected to a plug at the fuse box underneath the drivers seat. Through research, I believe it is connected to ACC. The guy or mechanic who have made this have cut some of the insulating material on the thick white wire and soldered it together with the positive wire for the LED.

I was watching some videos and posts on some faults regarding the main relay. I will look into this later and do a post of my progress.

Thanks again

Keizer

I think I might know where the problem is. I checked my main relay today, I put some new solder on the connections to be sure. And checked the connections with a 12V power supply while measuring continuity. When i plugged it in the car, it wouldn't power on. I have measured the connectors on the plug for the relay, and there is no voltage at all.

A guy posted a thread that he was able to get it to work by cleaning the grounds, I have done the same but without luck... Whats the next step, does anyone know where the main relay is getting power?

About the LED, it blink 2 times a second. It's attached to a white wire which is one of 5 in an 8 terminal green plug above the fuses under the steering wheel . The colors on the wires are: white, red/white, red/green, red/blue, red. and to a terminal which I think is accessory. it will also flash if attached to "dash light" terminal but then it's more powerful.

Former User

Check fuses 44 and and 13. Are they blown?

Keizer

I checked the 44 and its ok, i haven't checked 13 today, but I have been testing all the fuses in the fuse box under the dash a few days ago. Chances are it might be blown, but i'm not sure. It's 10.30 PM here in Denmark, so I'm gonna check it tomorrow. Thanks

Former User

Voltage is delivered from the battery to the main relay via 15A hood fuse 44. If the main relay connector fails to receive voltage from fuse 44, then you have a broken wire or bad hood fuse box.

Keizer

The fuse is unfortunately ok. I unscrewed the fuse box and discovered a quite thick blue/white wire was a little scratched, so there could have been a chance of a short. I tried turning the ignition on with the wires secured, and theres still nothing. I'm wondering if the ECU needs some kind of command before it will enable the rest to get power. The ECU is getting power from the green connector, pin 10 to GND like posted before.

Would it be stupid to try power the relay directly from the battery, and if is there a common GND or 12V?

Former User

Fuse 44 delivers voltage to the main relay plug via the Wht/Blk wire. Unplug the main relay and test whether the Wht/Blk wire terminal in the unplugged connector has battery voltage to body ground with the key off.

Keizer

I checked this guide regarding testing the main relay: http://autorepair.about.com/od/engin...nrelay_tst.htm

I unplugged the main relay and tried measuring between all the positive (3,4,5) terminals to body gnd. and there's nothing. I tried measuring continuity from body gnd to the gnd pins (8,2) and it seems I can only get continuity on pin 8 to body gnd?

Former User

Why would you use a guide not specific to your 99 Civic?

Get the service manual for your car.

Below is the proper main relay plug pin out for your car.

Test for voltage at pins 2, 5, and 7 of the main relay plug under the appropriate conditions. Pin 7 (fuse 44) is the one most relevant to our current discussion, but also test the other two pins for voltage.

Gunni

"It has to be said I cleaned up the engine compartment, but was able to start the car afterwards and park it "

Did it run before u cleaned the bay??

Keizer

Yes, I was driving the car before and nothing was wrong with it at all. Then I parked the car in the garage after cleaning and letting it dry.

I've checked the pins, and I have voltage on pin 7 and gnd on pin 3. Maybe I should check the relay once again and the fuses?

Former User

Keizer

I have 9-10V on pin 2 and 11.5-12V on pin 7. Pin 5 does not have any output. I get a voltage of 11.5-12V when measuring on the tab fuse no. 13 sits in.

Former User

Did you test pin 5 with the key in ON(II)?

Keizer

Yep

Former User

Voltage test installed fuse 13. Both tabs have battery voltage with the key in ON(II)?

Keizer

I get 11.40V on both tabs with the fuse installed.

Former User

The Yel/Grn wire is broken somewhere between the dash fuse box and main relay connector. Locate the break and repair or run a new wire.

Keizer

On mine it's YEL/RED. I have a YEL/GRN but that's on the output for the fuel pump pin 4. Thanks a lot, I'll try running a new wire

Former User

Verify that Yel/Red is correct wire. With key off, test for continuity between pin 5 and fuse 13.

Keizer

The YEL/red wire is not the correct wire. The YEL/GRN has continuity to fuse 13. It's pin no. 4 but still I don't have any voltage there when on ig2