Diesel car is turning over but will not start

Sorry for the slow response, we have been extremely busy, can you provide more information such as is the check engine, or security light on?.

I have bought a fault code scanner and there's an "EGR valve stuck" fault.

I'm convinced it's something in the fusebox and I tested the 2 purple relay sockets for fuel pump etc.. and the voltages on them are different which is VERY strange???

LEFT RELAY VOLTAGES:
top pin(87)= around 6volts
right pin(30) = around 8v
bottom pin(86) = around 8v
left pin(85) = around -0.2v

RIGHT RELAY VOLTAGES:
top pin(87)= 0v (please refer to paragraph below)
right pin(30) = around 8v
bottom pin(86) = around 6v
left pin(85) = around 1

It is interesting to note that when I plugged laptop into car and did tests, the "main relay" was always 'active' but the fuel pump relay was only active for a short while after turning on the ignition, and then it goes inactive. is this normal?

Let me be more clear sorry!!

Yes the EGV valve is stuck but I don't believe that is the problem. I believe it's the fusebox because of the voltage readings. :) thanks

What is the voltage at the battery? Should be 12.4 o 12.6

Best, Ken

Hi Ken, after many starts the battery went flat! having recharged the battery It was 12.8 BUT it did drop down to 12.1v.

I bought a new battery, it reads 12.5v and it won't start the car. I'm going to try and bump start the car with my friend.

So the engine cranks over or no? If not did you check the starter?

Best, Ken

Hi Ken, I have clear information now. yes starter is ok it turns over well. I clear all fault codes then I bump started the car today no problem. I then plugged the computer back in and it says,' P0683' fault code, which is glow plug circuit low voltage.

I am presuming it's the glow plug relay?

IMPORTANT NOTE: The battery is being de-charged by the car. over a few hours the battery will go dead if connected to the car.

fuse 38 and 39 seemed to be draining power, and also the ECU and Engine fuse (51) was draining a lot of power from the battery.

Yes, good call, glow plug relay or controller should solve the problem. Please let me know what you find. I would try the relay first. I don't have info on the 2004 Vauxhall Corsa, do you which fuses 38 39 go? 51 will always drain power as it is trying to power up on contact.

Yes, I actually tested glow plugs and they are not good. I put the spare in that I had but because of battery drainage, couldn't start the car. i'll have to charge battery tonight.

should fire with one good glow plug right?

it's not so cold here.

Yes it should, please let me know.

I fitted another glow plug relay and the battery does not drain now. The car started a few times but then wouldn't start. battery readings about 12.6v, Car does now start with jump leads from another car.

I found a bit of corrosion on wire conector inside the OTHER fuse box next to the battery, I clean it up, and car started, I ran computer, no fault codes. BUT THEN, tried to start car again and wouldn't start.

Same fault code appeared, B1485 - (2) Exciter Current Generator Terminal 61 Low Voltage - Present.

Any Ideas?

We are kind of flying blind with no wiring diagrams for the car here in the states, but does it have an glow plug controller? and have you replaced all glow plugs?

Best, Ken