nige8021

Have a look at this

Or in the service book

Have a look on this posting

The joint isn't a soldered one it's a mechanical crimp, so on the single wire you just double over the stripped copper so that it will be properly crimped the same as the two wires on the other end of the crimp

Use something like these https://www.ebay.co.uk/itm/261507747262?hash=item3ce3138dbe:g:WTEAAOSwZJdeuHqo similar items are approved for wiring repairs on Boeing & Airbus aircraft

Get rid of those nasty scotchlocks terrible things that should never be used !!

The battery in the fob has absolutely nothing to do with the immobiliser it's only for the central locking, the weak signal is often caused when you have too many other keys on the same keyring so blocking the RFID signal from the chip in the fob or the read coil around the ignition switch is being shielded by the extra keys

Have you proved with a multimeter that 12v is available at the roof aerial connection ?

That is the signal amplifier without that the signals will be almost unreadable On the PCG is a springy finger that is the contact to the actual aerial rod on my old Octy that was corroded and so was the contact point on the aerial rod once cleaned up it all came good. The other thing is are you running with an OEM radio ? if not the aerial amp will not be getting any power so it wont work you need something like this https://www.ebay.co.uk/itm/324304371984?hash=item4b820c0110:g:85kAAMXQgyZR-u~N to inject a 12v supply up the aerial feeder to power the amp.

They are also great if you've had a really hot curry the night before 😂

https://skoda.7zap.com/en/cz/fabia/fab/2006-453/7/721-721025/#30 #30 but you'll need to find the PR code as there are 3 versions listed, the PR code will be on a sticker in the boot (spare wheel area normally) or in the service book if you have it

https://skoda.7zap.com/en/cz/fabia/fab/2014-697/1/145-145047/ no mention of a magnetic clutch ??

Bicarbonate is too soft to have any effect on glass you need as I stated before Jewellers rouge

I guess you could possibly tee into the signal wire from the camshaft or crankshaft position sensor as that will be a pulsed 5v but quite how you could calibrate that to actual RPM ??

The tacho feed is from the engine ECU via the CanBus to the speedo pod so you'll need something that can get the RPM signal from the CanBus feed

T-cut will be too soft to have any effect on glass it's only meant for relatively soft paintwork same with bicarbonate

Jewellers rouge with a little water to make a paste

https://skoda.7zap.com/en/cz/fabia/fab/2004-225/6/609-609020/

If it has Stop/Start then there will be a monitor unit in the negative lead and then it will need to be coded so the system knows it's a new battery, if no Stop/Start then fit and forget

Have a read of this VW Battery Discharged Diagnosis for Static Current Draw.pdf

As to the wiring, for the OEM trailer controllers it's a couple of power supplies from the fusebox & a twisted pair of CANbus wires into the BCM then the 13 wires out to the trailer socket

Some OEM units have component protection built into them, that links them to the vehicle VIN # mainly the higher value parts like the radio/nav systems or speedo's and these will need a dealer with ODIS/VCP to remove the protection but I doubt the trailer control module will have and the coding is simple just look at the Ross-Tech Wiki about retrofitting

VCDS can not read the PIN codes you need either of the programs I mentioned then when you have the PIN you use VCDS to swap the PIN code into the replacement unit, there are two youtubes about it on the Ross-Tech wiki site

You need to refit the original speedo, read the PIN code with VagTacho or VagCommander, refit the new speedo and do the same, then with VCDS you can swap the old PIN into the replacement speedo and that will then work

OBD11 or Carista can do most of what VCDS can do but for level of service I would go with VCDS get the 3 VIN one then if you find you need more you just pay for the next step up to 10 VIN