Not exactly a question - more a story which happened to us. 1998/S Pug
306 1.4l.Saturday night, wife tried driving home. Started car fine, turned on heater, fan etc. Adjusted the air vent and everything died. Couldn't get the car to restart although the starter was turning fine. In the end got a lift home from a friend, but found central locking to be strange (not all doors locked etc - but drivers door wiring has always been a problem).
I went on Sunday morning to take a look. Sure enough, couldn't get it started but starter was turning the engine okay. Turning the fan on with ignition on made weird fast clicking noises from a relay in the dash somewhere. No sound from the fuel pump priming either.
Before going I'd looked on here for some common problems, one being a dodgy coil pack spiking the ECU. So had that at the back of my mind.
We'd also had some problems with the radio (gave up the ghost a month or so ago after it having long term problems). So I disconnected the radio and tried starting it again. It started this time. :)
I then tried driving it along the road - hoping to get home and whilst it seemed okay, the speedo and rev counter was going bonkers. Speedo reading 110mph (in a cul-de-sac!) with rev counter going from 0 to
6000rpm every few seconds. In the end it just died. Tried starting again - worked. Drove a bit further with the dials etc going bonkers before it stopped again (on a corner, halfway up the kerb, and the rev counter stuck at 2k rpm with engine off!).I'd pretty much thought the ECU was playing up - causing all the dials etc to go bonkers - but I wasn't sure whether all those things were controlled by it.
Anyway, gave up and called the AA out. Within 20 minutes they were there and took the history of the problem. Got it started (like I had) but died when foot on accelerator. Repeated a few times until it wouldn't start at all. Put a jumper battery on and it did the same thing - checked the voltages and battery connections - all fine. Then he put his arm down the back of the engine and after a few seconds said "That's your problem - broken earth lead on the gearbox".
The -ve terminal on the battery was connected to the geatbox by a single cable with 3 ends (actually 2 cables, but with a common crimp where they meet). Whilst the gearbox WAS connected to the battery, the lead coming from the gearbox to the chassis wasn't. This explains why the starter worked (earthed through the engine?) - but systems earthed through the body weren't - like the ECU!.
Took him about 30 minutes to fit a new earth cable (and he did it very nicely, removing the protective corrugated cover from the old one and fitting it to the new one etc). Was charged £4.54 for the earth cable and I was back home within 1 hour of him arrving. And as he said "You wouldn't have known it wasn't the original factory part" - very true - looks perfect - he took the time to fit all the cables back as they were which I'm sure some garages wouldn't have done. Interestingly, the old earth lead was quite slim, whereas the replacement was a more substantial diameter.
As an added benefit, the radio which hasn't worked for a few months, now works. Strange that was the only thing which didn't work for ages - if that was the problem - I'd have expected everthing not to have worked if the radio didn't.
So, it was a nice easy solution, fixed very quickly and professionally by the AA, and not the horribly expensive new coil + ECU solution I had in my head. I wonder if I'd tried it with a garage, whether they would have charged me £4.54 + 30 mins labour, or whether they'd have sucked in through their teeth and said "Sounds like your coil pack has packed up, probably spiked the ECU - total cost about X hundred pounds!".
D