Td5 blowing fuel pump fuse?

My td5 is refusing to start because I cannot hear the fuel pump running. On inspection I could not hear the relay firing so checked the fuses and the 20amp fuse had blown circled below:



Any suggestions for the usual places to check or could this be anything and I just need to chase the wiring along?

Although the relay and connections look to be in good condition I think for the price of it I will get a new one. I currently have a black on (unlike the yellow for the rest) and it has no markings on it, I do not knw if this is original or not. Does anyone know the part number for the fuel pump relay?

Having done a bit more reading I am assuming the black one in my set up is the fuel pump relay



However on have a bit of a play around i am struggling to work out what relay should be active and doing what. But it seems the pump is drawing too much current. It starts up runs momentarily and then the fuse blows. So do not think it is the relays that are the issue. I am familiar with the need to either drop the tank or cut an access hole to replace the fuel pump but is there any other testing I can do before needing to so that to confirm it is the pump and not something else that is the problem?

Well after a bit more investigation I can confirm the fuel pump relay appears to be the top yellow one in my pic above and has the white and purple wiring. Removing that and hot wiring the relay still blows the fuse, so it is not the relay that is at fault unfortunately. Before I cut and access hole in the back to run a hotwire to the pump form the relay live is there anything else I should be checking. I going to run a hot live direct form the relay live to check if it is the pump or the cable run that is causing the fuse to blow. To test either of these I will need an access panel cutting and plan on using a boat/motor home circular access panel similar to this (link) Can any one confirm the diameter that is needed?

Also I have found this thread (link) on another forum detailing where the centre of the hole should be, can anyone confirm this is correct and will work for my 90 as well? I assume they are all in the same place and there was no variation through the model years?

I know this thread feels a bit like I am talking to myself but someone else must have had this issue and be able to share their experience, on googling and searching the forum td5 fuel pump issues seem very common.

Well despite no other comments I am going to continue to update this thread with my findings in case it is useful to someone in the future.

I cut a small access hole in the rear floor to give me access to the pump wiring using the measurements from the forum in the above post. Although I know I will need to cut a larger hole to actually replace the pump this was as much to give me a view to check positioning as anything else. I am hoping that I will not need to cut the cross brace to the right and with a larger hole will still have enough access and clearance to replace the pump.



On removing the pump plug I immediately found what looked to the the case of my blown fuse. the plug socket on the pump had melted.



Running direct wires from the relay to the pump and from the rear loom plug to the pump (pic below) neither of these blew the fuse.



I then carefully reconnected the loom plug making sure the loose live terminal of the pump was fully in place in the loom plug and retested at each point in the loom and again did not blow any fuses. So it looks like the cause was the poor connection of the live at the pump, which has been caused by the plug melting which I am guessing has ben caused by the pump drawing a higher than normal current probably because it is beginning to fail or block.

I now have a working pump again in the short term while I order a replacement to make sure the plug socket is fitted correctly. Hopefully a new pump will solve all the problems. Does anyone have any recommendations on brand to go for?