Fuel pump? Relay? Wiring?

I changed the front - rear brake pipe today on my 110. All went well, bit of a wiggle getting the old one out and the new one in, but I wasn't forcing anything.

All connected up, and I went to start the Defender up, and on 1st ignition where the fuel pump should kick in I heard a light groaning sound, followed by a relay clicking frantically, a relay which must be the Fuel Pump relay since I've only turned the key one click, and I can't hear the fuel pump running, as is normal. Along with the clicking, the dash lights flicker ion and off with the clicking.

I checked all the visible wiring near where I was working, I had moved it, as I had to to fit the new brake pipe in, but can't see any visible damage. Nor can I see any damage to the earth strap, just next to the f-r brake pipe connection in the foot of the engine bay. I also pulled the relay and had a look at it (looks fine).

I thought maybe it was the fuel pump which was knackered, but I've seen that before, and the fuel pump just doesn't work, there's no clicking from the relay.

A couple of points to mention:

Vehicle has been sitting for a couple of months whilst I attend to some jobs.

It has very little fuel in it, and whilst I was working on the brake pipe it was jacked up at an angle on one side. However the same problem occurs when on the flat.

Battery was quite low due to having been standing, but I put a new fully charged battery on to test and the same issues are being had with that.

I'm beginning to think that there's a split in the wiring somewhere, that I've disturbed when moving some of the loom to fit the pipe in, but that's going to be fun finding!

Thoughts?

Just been out again, gave it a go, and it's actually making an electrical frazzling noise

Hope it aint the freaking ECU that's fried.

Sounds like a corroded earth? Do the lights work on full and/or dipped beam? Does need the fully charged battery, hopefully you still have access to that to get you running.

Battery fully charged (well, replacement was)

The earth lead was disturbed, but seemed okay. I will have a better chance to look again tomorrow morning.

Right, today I've been out for most of the day checking all the electrics. I've taken off, cleaned up, and copper greased all of the earth leads. I've also checked as much as possible all of the wiring around the areas that I would have disturbed, it all seems fine.

First thing you notice when you turn the key is that there's a buzzing coming from the relay, if left on this buzzing turns to the relay clicking very quickly. It's the yellow relay, which AFAIK is indeed the fuel pump relay. The dash lights also flicker, the temperature gauge goes upto half way even though it's a stone cold engine and there is no glow plug light, however I'm sure I seen one yesterday :scratching_chin:

All the fuses are fine, and if I pull either the 30a main fuse, or the 20a fuel pump fuse, or indeed the relay itself, the buzzing/groaning and clicking from the relay is gone, however temperature gauge then shoots up to max, and still no glow plug light, but I'll assume this is due to the fact that the glow plug relay needs to 'see' the fuel pump relay activated?

Annoyingly I don't have a suitable spare relay. The relay in question is a Siemens v23134-b52-x130. There's 4 pins to it numbered 86,85,87 & 30, but the relay diagram is faint to the point it's non existent, and I can't tell where the 2 terminals for the fuel pump power are for me to bridge, to see if I can rule the relay out that way.

I have to be honest though, I've never had a relay fail on me this way, usually they just don't throw as the solenoid is stuck. Which leads me to think that it is still the wiring somewhere, shorting out the relay... I just can't find where! The weird happenings of the temperature gauge also lead me to the wiring and not the relay.

Does anyone know which terminals I need to bridge to rule the relay out? I can't get access to any wiring diagrams.

Any ideas before I break it for parts :mil83:

Anyone?

Really at a loss with this one because I don't have a wiring diagram

ecu earth okay?

Yeah it seems to be chap. I've pulled all the ECU wiring to check for faults and in doing so cleaned up the short earth and checked continuity at the earth point.

The starter relay for TD5 pin out as follows:- Pin 30, brown/white from the 60amp fuse, 87 goes to starter motor (brown/red). 86 is from the ign switch to the relay coil, white/red, and 85 goes to the alarm control unit, black/orange, presumably to an earth from this unit. Hope that helps?

Further thought... Have you tried tapping solenoid at end of starter motor with a hammer? most starter problems caused by this solenoid, easily repaired with kits on ebay.

Thanks for that Derek, I'll keep a note of it for future.

I went out to it today, having left it with the battery off over night, and having gave the relay a good tap, and the bloody thing started first time, and have had no problems with it since.

Either something went a bit wacky with the ECU when I swapped the battery over, and having left it disconnected overnight has reset it, or I've disturbed the relay enough for it to start working again!

I've got a new relay coming on Monday anyway, at £3 it would be stupid not to, but I guess either of those things could have been the issue.

Appreciate the help, and I've made a note of the terminals on the relay for future reference