Car broken down with orange keylight flashing. Starts up for 20 seconds if you replace fuse?
 

My 1999 Citroen Saxo East Coast broke down. It has an orange flashing keylight but if you replace the 20 amp fuse in the engine fusebox it starts up for about 20 seconds, sometimes a minute before it stops working again and blows the fuse.

https://www.youtube.com/watch?v=EWbqV2ecL9Y

That should be the fuel Injection relay, obliviously if the fuse breaks it won't start as you will get no fuel supply,you need to find why the fuse keeps blowing,check that injection relay under the ECU in the engine bay and follow the wires from there and see if anything obvious show up.

Thanks bro appreciate your help I'll give it a try. I actually contacted my mechanic who's told me that it might be because I've stupidly been putting in E10 fuel, despite the fact it's a 1999 Saxo, he said anything before 2000 really shouldn't be using E10 and maybe the car doesn't like the old fuel. Do you think that could be causing a problem with the fuel injection relay? can putting in fuel the car doesn't like blow the fuse over and over? I'm not very mechanically minded but trying to learn for the sake of loving old cars like a Saxo haha

It's nothing to do with E10. All of these cars are E10 compatible.

you're absolutely correct, putting fuel in a car cannot blow a fuse!

The "fuel relay" is actually the main relay. It supplies power to the ECU as well as the fuel pump, injectors and coil pack.

It doesn't blow straight away, leads me to believe a wire has probably rubbed through somewhere. Or the relay is on its way out. There's 2 types of Relay. Black and Brown. replace like for like if there's no broken wires.

Just to double check, your car doesn't have an automatic gearbox does it?