Newbie needs help before i lose my hair ???

[Robert K]

Hi all. Please bear with me, as I'm new to all of this.
2016 T6 Hline 2.0tdi euro 6 bmt 50 k miles panel van lwb. So I jacked my van up 2 week of January to fit spoilers etc and new wheels, plus waxoyl behind wheel arches and floor plan. Finished all work last week and went to drop her down, and now she won't start.
Turning over quickly enough, but just won't fire. Called RAC and they said it was fuel pump in tank. So I jacked up again, and put a direct 12v supply to pump, and it works fine. There's no power going to pump from loom, although fuel gauge working fine with over 1/2 tank of diesel. Tried new relay under battery. Still no power. Any help would be so grateful as I'm at the end of my rope.
Regards Robert

 

[Grim Reaper]

The wiring to the lift pump goes from the right hand side of the centre of the dash area (just above your left foot) under the flooring to a pass thru beneath the passenger seat, there are no connectors in that run of wiring, have you damaged a wire doing any work inside the van? Blue and yellow wire if I remember correctly.

 

[Robert K]

Hi. THANKS FOR REPLY. I haven't done any work inside the van or near the flooring. Just removed plastic skins from underneath and waxoyled with spray gun. Fitted travelinlite front spoiler and grills etc, I've been nowhere near those wires, but as I said, I checked for power to pump, and nothing with or without ignition on. Can't understand it. Starting to wish now that I would of kept my 2.4 t4 1995. Lol

 

[Robert K]

I called VW today, they were not very helpful. All they said was that I need to get van to them to diagnose it. When I said its not driving, they said yet again, you need to get the van to them. I would need a land rover or similar to tow, with no steering or brakes. Not good advice I thought. So this is why I'm asking here
Regards Robert

 

[JOG]

The work you were doing doesn’t sound like it would interfere! Silly question - do you have fuel? At most you’ll have sloshed some fuel around, maybe disturbed some crud in tank. Get RAC out to start it

 

[Dan Morritz]

Sorry to hear about this @Robert K - I’m afraid I can’t add anything, but this forum is mind-blowing in it’s ability to problem-solve... I’ve never experienced such a willingness to help others. I’m sure a few solutions may come your way.

 

[Niknak]

If you can get to the fuel pump plug unplug it and run a temporary feed to it and then you could drive it,

 

[Niknak]

Are you a vip member ? Cause the wiring diagrams will show you the connections I know the wiring is under passenger seat then runs to centre and forward, can you lift the matting in the front and get to the connectors ? Had a couple of wiring problems caused by water leaks in the cab area effecting the connections

 

[Robert K]

Not vip yet, this is all new to me, but I like so far. I've already put direct feed to pump for checking if it works, and it does. So if need be, I will connect a battery up inside cab and run wire to pump to drive to unhelpful VW

 

[Niknak]

Take a jumper out the fuse not to it easiest way instead of a battery

 

[Robert K]

I thought of battery on crocodile clips, then I can undo when I have to stop when I reach VW, if I don't get to fix myself. I only bought this van 4 months ago after 3 years of hard saving. Very hard saving. Lol

 

[Grim Reaper]

What else could cause the no power to lift pump? How did you test the pump feed? across the two wires? Do you have a multimeter? Is there no positive supply with respect to an alternative earth? is there an earth connection on the negative wire at the lift pump? Has an earth been disturbed somewhere else (Common earth terminals in the engine bay area seem to be common to a lot of things that are nowhere near the engine bay, someone else on here had an issue with a common earth terminal under there somewhere) Check all the fuses, Immobiliser not reading the key? Try a starter battery disconnect, short pos and neg van side wires (not the battery terminals!) to clear any faults in the ecu and reconnect.
The only thing I'd be concerned with powering the lift pump off a non permanent feed is starving the High Pressure fuel pump should the connections come off or the battery die.

 

[Robert K]

[QUOTE="Grim Reaper, post: 353367, member:
I agree with you about live feed, so as we speak I'm making a cable up and have a spare battery that I will keep in cabin with me, until I get to VW.
I crossed the wires at the pump with feed + & - at the plug on side of tank and pump fired up. Van also started and run until I disconnected the power, but I've just noticed that she won't lock with remote control. So another problem to sort or maybe linked
Regards Robert
P.S have fully charged spare battery and charged van battery and got professionally tested. All fuses checked and fuel pump relay changed underneath battery. I've tried just about everything I can think of. As you can see in my photo, van has just been done with kit and full polish, and now no go. So disheartening

 

[Grim Reaper]

The Lift pump gets its earth at point 1 (366) in main wiring harness, not the same point as the fuel level circuit.
Positive feed is direct from the fuel pump relay though there is a cross connection to fuse 30 in fuse holder B (wherever that is) you should be able to check for voltage at that point to confirm voltage coming out of the fuel pump relay.

 

[Grim Reaper]

Earth point 366 is fed from Earth point 636 (Onboard supply contrrol unit) which is somewhere in the middle of the van floor level.
If it's the earth that's missing it's just a case of providing at bypass to another earth point until you can find the faulty one.

 

[Pauly]

If you are missing power and van wont lock etc then i think its safe to say you have an electrical fault
Personally i would be aiming to get a scan of the van to check for any errors and may help guide you, would at least see if multiple items are awol or if its an isolated problem

 

[Robert K]

I have checked fuse visually in engine bay and tested it in place. Power both sides. Relay is a different matter. Just swapped it out for a new one. Still no power from live at tank. Earth point 1 366...? Not sure about this or where it is.
TBH I'm at the end of my rope, and thinking of just taking to VW and let them sort the problem. I've been at it for a week now, and my head is fried, working in freezing cold winds, snow and rain. Lol
Regards Robert

 

[Grim Reaper]

I crossed the wires at the pump with feed + & - at the plug on side of tank and pump fired up.

I don't understand this bit.. The two wires that feed the lift pump are + (Blue/Yellow) and - (brown) in the plug on top of the tank. did you use a meter to test the two wires for the pump in the plug and got no reading? Did you try an alternative local earth (from say the bodywork) while still connected to the positive (blue yellow) ? Did you check (using resistance setting on meter) for continuity between the brown wire in the plug and a local earth from the bodywork? What was the result?

 

[Niknak]

Like I said earlier check the cab floor as the y suffer with water leaking in and causing problems and the fact you have locking problems points at it more

 

[Robert K]

I don't understand this bit.. The two wires that feed the lift pump are + (Blue/Yellow) and - (brown) in the plug on top of the tank. did you use a meter to test the two wires for the pump in the plug and got no reading? Did you try an alternative local earth (from say the bodywork) while still connected to the positive (blue yellow) ? Did you check (using resistance setting on meter) for continuity between the brown wire in the plug and a local earth from the bodywork? What was the result?

I didn't check with multi meter. i used old fashioned way. Followed wires to find out what did what. X vw mechanic told me colours to go for, blue/yellow and brown with yellow squares. This connected to spare 12v battery and pump fired up at plug coming from tank. As far as other end goes at feeding plug, no power with light tester and earth connected to body for feed test.
Regards Robert