Fuel Pump Fuse just blows.. - Land Rovers Only

Swivelball · 07-03-2009, 01:25 PM

Hello all!

My first post! Nice site you have here. Glad I found it now that I'm having a technical issue. Maybe some thoughts here?

1996 D1. Leaving work yesterday, without warning, engine just died. Flatbed ride home.

Symptom:
Engine cranks, no start. Fuel pump does not turn on during the initial 5 sec as typical. Fuel Pump Fuse blows immediately (15a).

What I tried:
I replaced the fuel filter thinking that maybe it was simply clogged, but no change.

I pulled the connectors on the O2 Sensors (all 4) just to get a good look at the wires. No chafing or signs of damage.

I attempted to measure pressure at the fuel rail, but not getting anything there.

I pulled the connector off of the Fuel Pump and it show no signs of damage nor damage to pins.

I buzzed the harness from the Fuel Pump to the connector located behind/ above left rear wheel, and there's continuity.

Any thoughts on what to try/ check next?

I replaced the Fuel Pump at about 110K miles, now have 165K. I may just pull the pump tomorrow ant see if anything looks out of order.

I do appreciate any advice or ideas for this newbie to the site.

-Tom

antichrist · 07-03-2009, 03:50 PM

A common symptom of a bad pump is it drawing way more current than normal, and blowing the fuse.
That happened to mine. I determined it by running a fused (same amperage as the fuel pump fuse) line from the battery to the pump. It blew the fuse, so that told me it wasn't a problem anywhere else in the circuit.
If you do that, be very careful where you connect to the pump you clips aren't touching, and make your final connection at the battery, or somewhere away from the pump.

Swivelball · 07-03-2009, 05:07 PM

Thanks Tom. I'll try that tomorrow..

Swivelball · 07-04-2009, 10:30 AM

Woohoo! The test was a huge success. I now know my fuel pump is fine. I ran a 15a fused jumper from the battery to the pump, and the pump runs like a champ. Started the D1 and it runs as long as the jumper is in place. Swapped back to the original connections, and it's a no-go. Seems like my problem is a short somewhere. I did buzz out the small section of harness between the pump and the junction above the left rear wheel, but stopped there.

I'm going to need help on this one. I don't think I'll be able to trace this through, so I'm looking for a local independent mechanic. Any recommendations for the Sarasota/ Bradenton Florida area?

ihscouts · 07-04-2009, 11:40 AM

Do you have the Rave CD (download)? Wiring circuits galore.

Swivelball · 07-04-2009, 12:00 PM

I do not. Maybe an on line resource for this? I'll poke around the web.

Ah ha. Seems like I found a resource. 421MB! We'll see if it works.

The Green Oval - Downloads | Land Rover Data

ihscouts · 07-04-2009, 01:24 PM

I didn't have the link.....sorry about that. Very useful for restoring a rover to working, reliable condition.

Swivelball · 07-04-2009, 01:38 PM

No worries. I'm looking through the CDs now. Lots of good stuff although maybe too much of a good thing.

Swivelball · 07-07-2009, 10:35 AM

I think I've got my answer. I received some advice to pursue the idea of a short in the harness. After poking around the fuse box, and then the relay, I returned to the little harness between the fuel pump and the connector above the left rear wheel.

I previosly checked for continuity from end to end, and it was fine. Now I had a major WTF moment when I suddenly realized there was continuity between the white/ purple wire in this disconnected harness and the tail pipe. WTF indeed.

This short section of harness is sandwiched between the body and the frame. I'm thinking some genious at the factory did this during assembly. Now the wires inside the "sandwich appear to have shorted out. I clipped the white/ purple wire and spliced a bypass, and the truck fired right up.

So I'm running with the splice and have ordered the $50 replacement harness from AB now rather than wait for the other wires to short out.