740 Fuel supply problems

I have a slight problem with a friends 740 (2.3 8v carb) that I service, It cut out and there seems to be a lack of fuel pressure, If I remove the fuel pipe from the carb and crank the engine no petrol flows until the pipe is lowered down to the level of the sump when it seems to pulse out. I think the vehicle has an electric pump on the tank. I understand that the fuel pump relay is known to fail but I can't work out which one it is (I know a haynes book would tell me but I can't get hold of one quickly and my friend is in a rush for the car) If any one can offer any advice about what I should look for and check I would be very, very greatful!!!

Fuel relay is on far left, second row back.

the haynes manual suggests there is an in tank pump, but when i removed the tank cover on ours there werent enough wires for a pump AND a fuel gauge. ours only appeared to have the diaphram pump on the engine, which is what most cars with one have, i mean what would be the point of the diaphram pump if you already had an electric one? and vice versa. There is an idle control/anti run-on device fitted though, its a vacume operated valve on the engine side of the carb, it's controlled by a solenoid valve on the suspension turret. check the solenoid is opening and closing properly. (why they didnt just fit the solenoid on the carb like everyone else does, i dont know!)

On My 1986 740 B230K the fuel pump relay was green. As has been said on the left hand side second up. About 2 inches by 1 inch box. The relays are behind the ashtray and behind the fuses. To get to them pull out ashtay by pressing down centre clip. Then lift out the backing that says electrical fuses. If you need more room you can take the storage compartment out above by pulling out the lighter and removing the surround by gently prising it off with a flat bladed screwdriver. Behind this is a small phillips screw, take this out and withdraw the panel by pulling it towards you. Hope this helps James.