Thread: D1 fuel pump electrical issue

The fuel pump power passes through a number of loom connectors that can go wrong, notably the one above the rear muffler. Inspect the connectors closely and look for a blackened nylon housing. Also possible is the failure of the fuel pump relay and the actual fuse holder. With the engine running use a test light on all points along the harness for power in the white/purple striped pump feed wire. Somewhere you'll discover the dud connector.

After my initial post I thought yep why not, let's get radical here and actually consult a manual. I know, I know, not the done thing but as they say when all else fails. So after consulting the Oracle I have checked the fuel pump relay. There is also a inertia switch, conveniently located behind the windscreen washer water tank. Can this be a issue?
I will check the wiring from the pump back to the relay,etc.
Cheers Hall

So I have had a look for the wiring from the fuel pump. I know it goes somewhere, just where is a mystery. Does the wiring from the pump run inside a Disco? There seems to be nothing in the way of wiring underneath running from the rear to the front.
Cheers Hall

Originally Posted by Hall

So I have had a look for the wiring from the fuel pump. I know it goes somewhere, just where is a mystery. Does the wiring from the pump run inside a Disco? There seems to be nothing in the way of wiring underneath running from the rear to the front.
Cheers Hall

Did you look above the rear muffler? Hanging off a clip under the floor is the first connector, like I said. Then trace the loom around to where it goes inside, behind a tail light perhaps.

For whatever reason this Disco only has one large central muffler. Think I have found the problem. I removed the bolts from one end of the tank allowing it to tilt down and give access to the wiring plug. When I checked the plug it had a burnt pin slot on the earth. So possibly no earth. So visit to a local wreckers in on the agenda.
Cheers Hall

The fuel pump wiring plug on some D1s is actually part of a link lead between the pump & main harness. If that's the case with yours, it might be easier to replace the link lead itself rather than fiddle around with the plug, especially if it's been heat affected already.


STC3683 is what I used to repair the burnt connector on my P38:

All sorted now. It was the plug. Went to Jolly Roger wreckers. Got a good plug with a bit of loom. Did a bit of grafting. Tried to start the Disco could hear the pump but still not starting. One issue that I contributed to when I first tried to start the Disco. The new fuel pump was a generic brand unit that did fit. There was on the old pump a length of plastic concertina pipe. On the new pump I had used a length of normal fuel hose. When the fuel pump housing closed together as it does it had crimped the fuel hose. So I had to remove the tank again and adjust the length of the hose. Which thrilled me no end.
Cheers Hall

I hope you used the correctly rated submersible pressure hose, otherwise you'll be doing it again in about a month after it bursts. That concertina hose is the correct stuff and should be reused. Normally I break up the old pump outlet with a hammer and a block of wood then shake out the bits so I can clamp it up to the new pump.

Oh and I suppose you know about the access hatch under the rear load area carpet in a D1, makes the pump job a load easier.

Hose example:

444 Series 8mm 5 16" IN Tank Submersible Unleaded Diesel Fuel Hose 444 05 IT | eBay