Breezy_Pete

So, for reasons unknown, the 'key turned to unlock position' info is getting corrupted on its way to window motor. Bad earth is a possibility, for sure.

There is no way to do that, unfortunately. It's controlled locally by the motor modules, no central connection or involvement. Key tuned signal goes to module, module talks to its opposite number on the other door as required. Window motors are invisible to diagnostics and CAN systems. Up until March 2010 anyway.

That's going to take a bit of detective work; that fuse supplies all sorts! Charcoal filter purge valve Secondary air pump relay coil Secondary air inlet valve Both lambda sensor heaters MAF sensor.

If G65 isn't giving a sensible pressure reading, A/C will not be operating. The fan should not be expected to work via refrigerant pressure increase, if there is no such increase, nor any signal telling the HVAC unit about it.

I think your cheap Chinese thermoswitch may be working OK, depending on where and how you are measuring the coolant temperature. The thermoswitch is sampling the output temperature of the radiator, not the engine coolant temperature as it is at the temperature sensor. Clearly the point of the radiator is to reduce the coolant temperature, so you should expect the output temperature to be significantly lower than the input temp. It does seem like you may not be getting good flow through the radiator though; coolant pump, thermostat or blockage all could be involved, I guess.

Made this little image just the other day for someone in the mk2 section. Your circuit board probably looks slightly different, but pretty sure the pins for inputs and outputs are the same. If I were you I would focus on what the voltage is doing at pin 10 (LTS input) when indicating left, using stalk. Should be high (12V, I expect) when stalk is in neutral position. Should go to 0V when indicating left. LTS = left turn signal, RTS = right turn signal. Hazards input will be on another pin, and seems to be confusing the issue a bit, by trying to operate simultaneously with stalk-controlled inputs.

Pretty sure it's the 1.2 TSI engines that have problems with fuel rail bolts. https://www.briskoda.net/forums/topic/468348-fuel-leak/#comment-5257257

Have a look at strip fuse no.6 in the fuseholder atop the battery first; cracking of that is probably the most common cause of it being lit (and possibly obscured).

Threads are sequences of posts like this one. If you look at any given subforum, the titles of the first post of each thread tend to be describing the problem that's about to be discussed. Bit like a non-fiction book title.

Should be this, I think:

Are you certain that it isn't the belt tensioner pulley that's screeching? More common, I think. Belt for non-A/C version of your engine is 21.8 x 1453mm long. No reason it shouldn't work if routed correctly. Diagrams can be over-generic and confusing.

You may find that chip looks visibly destroyed if you open up and inspect the BCM circuit board. Nothing else is involved; if the input from stalk and output wiring to the lamps is OK, and fuse is OK. Can test all of those things with multi-meter at those connections I've shown.

Some more info for you, including inputs and outputs (inputs are just switched to 0V/earth by the stalk). Outputs go to the front, rear and side repeater lamps, all in parallel for each side. LTS = left turn signal, RTS = right turn signal.

Did you disconnect the battery before doing the work? Reconnected?? What is happening when you try to start it? Cranking, or nothing?

If you are 100% certain that the 15 Amp fuse number 49 is OK, then there may be visual evidence of failure of the integrated circuit in the onboard supply control unit (BCM) having failed. It's the large chip to the right of the white relay in this photo:

It's a bolted-in assembly that you replace. No pulling involved.

Use continuous mode whenever it's raining enough. Massively less wear and tear on relay contacts, and no noise.

Find the BCM and put soundproofing material between it and you.

Check for loose or corroded connection to starter solenoid.

Pretty sure it's a Torx fitting, so hex will not go well.

Wheel cylinder is the usual description in English. Careful with the single screw fastening accessed from rear of backplate. Can't remember if it's Torx or hex, probably the former. Easily rounded out with insufficient tool insertion due to corrosion.

According to oemwolf.com that 5N0505235Q part number has been superseded by 5N0505235AC, then that in turn by -AE, and that by -AG.

If it's a 2007 car, the first one. That means "for cars built up to and including 21st June 2009". The second one is for cars built from 22nd onwards. But as this page confirms, they're equivalent, so it probably doesn't matter: Bonded Rubber Bushing Febi 6R0501541A (skoda-parts.com)

Check cabin fuse No. 2 (5 Amp), and under bonnet fuses No. 4 (20 Amp) and No. 25 (40 Amp).

I'm sure it'll be fine, but you should prioritise finding why the level has fallen. Consumption of coolant should not occur.