Another year, another decade, another pile of poop.
Cooling fan staying on constantly, even though ignition is off (i.e. listening to the radio, fan is running).
Interior suddenly steaming up when stood.
Alarm beeping once (loudly) when locking and once (loudly) when unlocking; usually 2 quite beeps when unlocking only.
Slight squawk from the front end occasionally when giving it the beans; harmonic balancer?
Battery voltage showing low prior to starting; starts absolutely fine with no hesitation, seems to be charging fine.

Seriously thinking about getting another Alfa as the ones we had were way more reliable than the recent run of Jags.

 

Look at the contacts on the ecu located on the passanger side at the feet. Water Comes in from the enginebay into the contacts.

 

So, Sir_daniel.
When you say 'passenger' side, do you mean for a right hand drive or a left hand drive car?
It would help if you put your car model and location in your signature.
That way we can decide whether or not to take you seriously!
Not a total waste of time stripping out the wrong footwell (found a spider) but the time could have been more productive.
No water either side by the way.

 

This one easy, either the radiator switch or the relay, you'll find plenty info here about it.

You have a small water leak somewhere, undo the black panel under windscreen on each side, lift it by a few inches up only so you wont have to remove it completely and see what's hiding in there. Hopefully no surprise rust holes in there

Inspect the alarm siren in the right corner, just at the bottom of windscreen wash reservoir filler neck. Other than that I assume you have a remote and you unlock with it?

More likely a belt or tensioner or even alternator or water pump or ac compressor bearing, these are consumables after all. Harmonic balancer easiest to check though. Just mark the whole thing up with a white pen, drive for a while and recheck.

Meh, ignore, mine showing less than 11V on startup for the past 5 years, still going strong.

Reliable Alfa? Seriously.........

 

https://www.jaguarforums.com/forum/x...u-x300-118790/

Look at the red and black connectors for corrosion and also How the ecu looks (opened up 2 of mine x300 ecu that was non rinner and cleaned them with electric cleaner and a toothbrush), you might have to resolder some of the connections depending How it looks.

 

The car is not a 'non runner'; it drives absolutely fine.
Had my head up under both footwells, no sign of any moisture, anywhere.
Drove it in the dark today first time for ages.
Key in, position 1, radio and fan start, battery showing 11 volts on the gauge.
Engine starts on second rotation after turning the key.
Revs pick up and voltage picks up to 13 and a bit.
Lights on, voltage drops, demist on and voltage drops some more, engine running fine.
Pull away and voltage back to normal.
Earlier today, disconnected the battery and did a hard reset (remembered to find radio code).
Spent a while wondering if there was any point doing a hard reset in an old car.
Made no difference anyway.
Going to buy a new battery tomorrow.

 

Steve, those items of concern sound more like Jaguar "qualities" or "personality" than real problems. Most of which are probably easily resolved, i.e. according to Katar's advice above. I think you're a ways off from a pile of poop! I hear Alfas have many qualities and a personality of their own too...

 

Nope, not a usual characteristic at all, certainly not on this car.
All these traits are suddenly new although the alarm beeping once instead of twice has happened before.
Would the fan coming on before starting draw enough juice to drop the volts to 11.5? It's never done that before; does anyone know where the relay for that fan is as I would like to pull it to see what happens?
Decided against a new battery today, mostly 'cos it's about £140.
Borrowed one off a mate but it was all exactly the same. Drop tested mine and it seemed absolutely fine.
Got mine on the CTEK charger overnight so will get the voltmeter on it tomorrow.

 

Cooling fans are ok to be always on when the ignition is on. But they shouldn't run when ignition is at one click (for the radio on). Cooling fans should cut off momentarily when cranking, to send a little more energy to the starter. The dash volts gauge is only an estimate, so you will get a better idea of the voltage sag when cranking by using a real meter. The cooling fan relay is in the space forward of the left front wheel, down low. Subject to moisture and dirt, it could probably use a cleaning.

A loud high pitched beep from the alarm system usually means something is not fully closed, not latched. Perhaps a switch has gone faulty on one of the opening panels.

 

I only noticed the voltage drop because it was obviously lower than usual.
Put the fully charged battery on and the volts were quite a lot higher even though the fan was coming on.
I have ordered a replacement relay; do you access it through the wheelarch or behind the left side headlight? Damned if I can see it anywhere.
The switch at the bottom of the radiator, what does that control? I managed to disconnect it but it didn't seem to affect it; ordered a new one anyway.
Have a vague recollection from one of the cars that the alarm did funny things when the fob battery was getting low.
I'll try the spare one today.