Racehunter

Good point. There is a very slight sign of residue at one end of the battery, so will have a closer inspection. Cheers

Indeed. Probably changing the car this year, so have to take that into account

Quick update on the alarm/bonnet open issue. I didn't find any wiring issues at all , so took the car into my local Indy to check the stored info. This showed the 'bonnet open' activations as well as a alarm horn issue. The codes were cleared and for 10 days, the alarm acted as normal. Friday of last week, off it went again, with the bonnet open symbol illuminated and the alarm sounding, so I decided to pull out the alarm horn and leave the car for a day or so to see what happened. No further 'bonnet open' signals, so it looks like the alarm horn is the issue. I have just pulled the horn apart and checked the battery but this is showing 6.59v, so I think its still in spec, and probably not worth 'trying' a new battery. So, it looks like I have an issue within the board itself meaning a replacement horn. Now the question is, do I risk a S/H one?

@varooom Thanks for that. Is J519 in the drivers footwell?

Thanks. I had thought of that, but the fact that the MFD shows the bonnet as open, when the alarm goes off made me think it was more related to the microswitch or its wiring.

So, I replaced the bonnet catch and micro switch and all was well for around 3 weeks, until I got woken up by the alarm going off at around 3am! Unlocked and locked using the remote and some 15 minutes later, off it went again. I used the lock/key unlock process and disconnected the battery over Christmas but now its time to try again to resolve this issue, and my next step is to see if its the issue with corrosion of terminals in a harness connector block. With that in mind, does anyone have a 'walk-through' to get to the terminal block in question, which I believe, is somewhere behind the A pillar trim either passenger or drivers side? Oh and I did try the old microswitch again and still the same. The bonnet open is always indicated when the alarm goes off.

So, it is indeed 'normally open'. Only thing I didn't try, was to leave the connector apart and then lock it. All due to other urgent Sunday tasks! Will try tomorrow and report back. Who knows, it might help someone else.

Good point. I will check tomorrow.

Well, I tried it, but the bonnet open symbol showed on the MFD, permanently which means no wipers. Not ideal. Guess I will have to strip out the latch mechanism to see if I can see anything

I think I have a problem with the microswitch on the bonnet catch, as when driving, I keep getting a bonnet open warning on the MFD. Additionally, the alarm self activates frequently, which is annoying to say the least. As a stop gap measure, is it possible to bypass the microswitch, by jumping between the 2 female pins on the harness plug, after disconnecting it, or would it need a specific resistor to fool the system? Any help appreciated. Thanks

So, search for a used unit rather than a 'Chinese' head unit? Ok thanks for the input

Having scoured many posts about this subject, I have not really found the answers I need, so please bear with me. Firstly, my car. Its a 2009 Octavia Estate 1.8TSi L&K, so Bolero HU (no Nav or Bluetooth), Climate Control, F&R Parking Sensors, MFD etc. OK, I can hear it now, 'but its almost 13 years old, why bother?'. This car was purchased new by my brother in law, who, due to medical conditions, hardly drove it. He passed away in 2019 and the car had done 7000 miles at the time and the car came to me. It has about 30,000 miles now and is still like new, so I cannot see any benefit from changing it, hence considering a few updates. What am I looking for? Well, in no particular order, Bluetooth, Android Auto (wireless?), OEM fit and finish and the retention of the integration of parking sensors (sound and display), MFD, Climate etc. I have looked at a couple of units already, but when there are no reviews, its a bit of a gamble to simply purchase, so I would really appreciate any suggestions you wise sages might have. Thanks