Puma 110 won't start after transfer case overhaul

[POD]

G'day all,
I have a mate's 2010 2.4 Defender in my shed, it has been in dry dock for the past 2 weeks during which time we have overhauled the transfer case and fitted the modified gearbox - transfer adapter kit.
We finished putting the car back together at about 1am last night but now the car is refusing to start. Dash lights come on but NOT the glow-plug lamp, the engine cranks but does not fire.
First thing we tried was locking / unlocking to reset the immobiliser, have done that several times including leaving it locked for several minutes.
Checked all the fuses and there is one under the driver's seat that is separate from the fuse box and all on it's own, a 15a fuse, that blows when the key is turned to the running position. The diagrams in the owners handbook give no hint that this fuse even exists, much less what the circuit is.
We pulled the floor panel thinking we may have pinched a wire between the g'box and t'fer but all wiring is intact there.
Our next plan (I called it quits at 2am after 16 hours) is to check the wiring under the bonnet to see if we damaged anything, e.g. on the firewall, when we lowered the back of the transfer case for removal.
The other nagging thought in my mind is that I welded a puller onto the gearbox output shaft as per Ashcroft's instruction sheet, battery was disconnected throughout the job but hoping I have not fried anything. Earth of the welder was attached to the puller.
Would appreciate any helpful input, mate needs his car and I want my shed back.

[rangieman]

Do the pumas have a inertia switch under the bonnet :cool: If so have you tried that it could be that

[spudboy]

That wouldn't blow a fuse though...

[rangieman]

That wouldn't blow a fuse though...

No it would`nt but a pinched wire could . It is all about elimination of the easy ;)

[POD]

No wiser after a few hours spent searching for damaged wires etc. We have stripped the loom at the ECU looking for anywhere we may have pinched or broken a wire by tilting the engine, nothing suspicious. I don't think there is an inertia switch but, as mentioned, this would not explain a fuse repeatedly blowing. I am out of ideas and we are desperate for any advice.

[PAT303]

You put the earths back on?. Pat

[PAT303]

Is it getting fuel?. Pat

[justinc]

Yup thise 2x little earth wires on the rhside of the transfer case ate critical if they aren't connected to the case there is no earthing for ecu etc etc. The main relay under the drivers seat is sometimes a problem and not seeing the glow lamp on is one of the symptoms . Try jiggling the relays arounf and see if it starts. I have had quite a few with this prpblem. End up actually disassembling the plug and crimping the frmale connectors a little so they can make proper contact. Have even seen one all melted from huge volt drop....

Jc

[POD]

Thanks Justin, certainly the earth wires on the right-hand side of the transfer case were refitted when it all went back together but I will double-check that they have a good connection. I'll also try jiggling the relay connections- which is the 'main' relay?
The 15a fuse that is on it's own little holder under the seat is the one that blows when the ignition switch is turned on- can anyone tell me what it is the fuse for? I could not find it on the wiring diagrams. If I pull this fuse on my own car, it will not even crank- so there is something different happening here. Whilst investigating it this afternoon I have found that it has battery voltage switched on with ign on one side, and the other side has zero resistance to earth- which makes me think that it is a wiring short somewhere but I am well aware that this electricity is funny stuff.
Anyway will check that earth business first- gives me a direction to start looking which is encouraging.

[POD]

Is it getting fuel?. Pat

Pat I have to assume that it is not getting fuel, but whether it is a supply (i.e. power to the pump) issue or an injector issue I do not know- I don't have a means to measure fuel rail pressure and I believe they run several thousand psi at the rail; is there some way i can check this?

[PAT303]

I'd follow JC's advice and then do a fuel system bleed,do a youtube search for it,it's the same as if you ran it dry. Pat

[POD]

I have checked and rechecked all the earth points on the transfer case and battery, they are all connected and have good contact, problem remains. I have jiggled all the wiring to the relays under the seat, when time permits I will pull the main fusebox out so I can get to the back of all the relays and check contacts.
The fuse that blows when the ignition is turned on is all by itself on the end of a pair of wires taped to the loom under the driver's seat, a brown / orange wire that has 12v with ignition on and a plain brown wire that has zero ohms to earth; I'll check this on my own car but it does not seem right that the brown wire should be direct to earth when there is 12v fed to the other side of the fuse. Will get back when I have compared on my own car.

[bee utey]

In previous LR wiring looms, brown/orange stripe was a power wire that stayed on for a few seconds after the ignition was switched off, controlled by the ECU. Used for things like idle steppers, injectors, EGR valves and the like. I'm guessing that in your zeal to connect all earths that you've earthed the other end of the plain brown wire which used to power something like an EGR valve.

[POD]

It seems that if there is a 'worst possible' scenario, that will always be the reality- I have discovered that the ECU is fried. After several hours of checking everything else, I took the ECU out of the problem car and fitted it to my car- the problem came with it. So it seems that I have fried the ECU by welding the puller onto the adapter shaft. Can't believe my stupidity- I have always made sure to disconnect the ECU before doing any welding, but I was so focused on the damn adapter shaft that I completely overlooked it when doing this job. Unbelievable.
I will post a new thread with questions about ECU repair / replacement. Thanks to those who have offered helpful advice on this one.

[roverrescue]

POD
I feel your pain would be the sort of thing I would do!
At least there is a lesson for all. Even if you earth adjacent to the weld whacking a few hundred amps down the vehicles common earth isn't pretty in a puma ;(
S

[POD]

POD
I feel your pain would be the sort of thing I would do!
At least there is a lesson for all. Even if you earth adjacent to the weld whacking a few hundred amps down the vehicles common earth isn't pretty in a puma ;(
S

Yeah I was being very careful not to pass the welding current through any bearings etc but completely forgot about the ECU. Sucks that it is a mates car rather than mine. I think I've put in around 50 hours over the last 3 weeks getting his transfer case overhauled, intermediate shaft bushed etc- this is how it ends up due to a stupid oversight:(

[justinc]

Did you unlock it before trying to start your vehicle? The ecu needs to learn the security code from your 10as system in order to start. Or does it blow fuses too?

[AndyDuncan]

POD when you welded on the car, is there any chance even small that a terminal has been in contact with the body (Even the Earth)? A welder, stick, MIG and TIG make massive amounts of frequencies through out any metal connected to it. If your earths or positive leads were in contact with the car metalicly, even slightly, you have fried your ECU.

At all costs do not ever weld on your car, if you do, remove the ECU unit and put it away no where near the car, then once finished, earth the car to the ground (Dirt) to get rid of any residual currents, then reinstall your ECU unit. When they build these processors (ECU) they use special gloves to stop static electricity from a human which is at most in en extreme case 2 Volts, most times 0.2v. 0.2V is enough electricity to fry some section of an ECU depending on how advanced they are. (My brother builds Processors).

Id say if you haven't fully insulated your battery leads or disconnected all the earths your looking at an ECU, or if they can repair the one youve got.

Im a fitter and Turner by trade, and we never weld near bearings or anything as the way electricity earths, if its near a bearing it can make like tiny little fuse marks on the bearing race and then ultimately kill your bearing in as little as seconds to months depending on what it is. If we have to we make 100% sure the peice if fully insulated from the bearing, and the weld area is as isolated as possable with a nice shiny earthing area for the welders earth.

Hope this answers some questions

[AndyDuncan]

As far as security codes and stuff, it wont blow fuses, it just wouldn't start. To blow a fuse your getting wayy to many amps through that circuit. so like a diode or a regulator is stuffed in your ECU. Or if your very lucky they will have an external diode/ regulators, but, thats very lucky!!

Get someone with a proper scan tool and get a professional diagnosis at least.

[lump_a_charcoal]

He already said he blew the ECU...:(

[POD]

Did you unlock it before trying to start your vehicle? The ecu needs to learn the security code from your 10as system in order to start. Or does it blow fuses too?

I didn't lock / unlock to reset the immobiliser but the big clue was that when i turned the ignition on, it blew the same fuse in my car that kept blowing in the other car.

[justinc]

I didn't lock / unlock to reset the immobiliser but the big clue was that when i turned the ignition on, it blew the same fuse in my car that kept blowing in the other car.

😣 sounds power diode related...😠😠😠 i have welded quite a few bolts onto puma drive couplings and not had a problem... yet. Might stop playing Russian roulette then with the next one!😮. Sorry to hear this happened .

Jc