V6 will not crank after flat battery

[Mrs Feynmans Bongos]

Yesterday my V6 would not start or even crank, including with a jump applied.
I found interior light switch left at ON (ie not "Door"), measured the Battery at 5V
(It need only a tyre and front suspension drop links on MOT mid-Aug, then 800 faultless miles to the Lakes, before one of us left it on

But today (with the flattie swapped-out for charging) it's the same using a spare Battery @12.5V.
**Nothing** works apart from Headlights (battery drops to 11.9V), but it stays @12.5V when Key is turned to Start (does not drop a millivolt).
Auto Selector is in "Park" (where I left it), waggled it but could not move it.
All FUSES under the bonnet bleep when tested ie are short/good. Cabin fuses next ...

Advice appreciated.
Eg could some Relay have stuck? Surely a failed Starter Motor would still drop volts?

[g8dhe]

Is there a clicking noise when you turn to start at all? If so it might indicate that your starter contacts has worn out, quite simple to replace see eBay for spares.

[Mrs Feynmans Bongos]

Thanks for reply Geoff
No clicking, nothing at all when Key->Start

[teenmal]

Personally I would make sure that the engine is in fact turning (manually) and check earth and battery connections and battery posts(terminals) for damage and as Geoff said the starter solenoid .

[g8dhe]

The relay that provides power to the starter solenoid is mounted on the offside wheel arch and is the front one in a block of 4, A2-04

[teenmal]

Sorry missed this bit "Auto Selector is in "Park" (where I left it), waggled it but could not move it."

That would lead to a battery (supply )problem. Remember you need the ign switched on or acc before the selector will disengage from P.

[Mrs Feynmans Bongos]

Thanks for the diagrams.
(BTW, I can move the Auto Selector with my foot on brake , but no difference on going back into "Park")

Looks like Relays are inside rubber boots, or is that just connectors?
Is that A2-04 in my photo? (left of centre, level with O/S/F of spare Battery now in situ). [img]https://postimg.org/image/qoz8pczw9[/img]

Steve @Outback wonders if flat battery has upset any remote Immobiliser (I naively thought "Lock/Unlock" on my key were just for Central Locking )
If a confused Immobiliser is now denying ?Ignition Solenoid?, how do I un-confuse it? Eg judiciously pull a Fuse in cab, then reinstate it ... WHICH ONE?

[g8dhe]

Yes the relays are in rubber covers, they should pull up and off to gain access to the relay and to disconnect and check it.
Yes if you have an immobiliser, it most likely won't connect to any obvious fuse, however there would normally be a light on the Dash to indicate if its armed on not, on first opening the door it will normally go Green but if left for more than a few minutes without starting then the light will go Red to indicate that the immobiliser is armed and stopping you from starting. One obvious way to check if you have an alarm and immobiliser is use the key to open the drivers door and then try to start the engine, you should trigger the Alarm and the immobiliser, using your remote should then allow you to cancel the alarm and immobiliser.

[windywatson]

If the van didn't exhibit any starting problems what so ever before the flat battery. Then I wouldn't think that the battery going flat would have caused any major issues with ,blown fuses, faulty relays etc. I would think that it is going to be something simple like an immobiliser. I have an immobiliser that uses an additional fob on the key ring that it picks up signal from when in close proximity to the ignition key. I wonder if in your instance if there is an immobiliser that the very low voltage has caused a fault like memory loss if you get my drift.

[nth]

Is there a power supply going to the small wire on the starter solenoid when you turn the key to the start position? Does the starter turn if you supply the solenoid with power ? Need to be 100% the gearbox is in P or N before trying this.

[Mrs Feynmans Bongos]

Main 100A fuse had blown.
With Battery disconnected, I pulled+checked the rest, including cabin, all were fine. My V6 now starts

I think it must have blown when I tried in vain to jump the 5V flattie from my Focus (running ~14V, Silver/Calcium I think).
Fairly sure I applied the jump leads in the correct order, but I was in a hurry, and it DID spark

Fuse did it's job then. Will take it to work tomorrow, aiming to check everything electrical.
Thanks again to all you helpful folks.

[Bob]

Splendid job.

[g8dhe]

That fuse should not have been involved if you connected the jump leads to the battery terminals !
More likely something is amiss with the alternator, which might also explain why you had a flat battery in the first place

[Mrs Feynmans Bongos]

Noted, Geoff.

Alternator was a refurb. from AutoJap (fitted by Steve @Outback in July 2015 after Cambelt saga)

When my V6 didn't start or even click, I found Battery at 5V ("no load"), also interior light switch had been left at ON (?kids clearing wagon for me after 4h drive home, Aug BH). Only headlights worked. 2 days since Fuse replaced + 40 mile commute, I have just measured Battery @12.28V.

So Int. light ON for ~2 weeks seemed the likeliest drain. But I wondered if there's another path which led to Main Fuse blowing, also meant only Headlights worked. Testing all Cabin fuses, I found 2x 5A inline fuses retrofitted to X03-02, 08 (Cigar Skt, ICE, Int.Lighting?). Mild surprise but I'm no auto-electrician (yet ), is this ok, eg for UK radio? There also remains a Jap M'way charges box, but that remains unplugged.

[g8dhe]

Yes the only thing that could take a 100Amps or close to it for a long time is going to be the alternator, every other circuit on that fuse goes via the 60Amp IGnition-Key fuse which is 60Amps. So unless you managed to do something very odd simply connecting the jump leads themselves isn't the problem - however you did mention a lot of sparking which would imply a high current for some reason ... but difficult to diagnose after the event ....