Breezy_Pete

I believe so, yes. It's not showing you how to do trailer coupling wiring, it's showing how it's done from the factory. Do you mean the A5, A6 etc? They aren't connectors, they are inline splices in the loom(s).

The factory 'trailer coupling' wiring is as shown here: The various connections to the trailer light socket just tee off the feeds to the existing rear bulbs. 13-pin socket wiring is shown, 7-pin is obviously simpler and probably what most people will do on a car of this age. The function of the bypass modules that gives you a beeping in time with the direction indicators being used is actually built in to the Fabia electronics as a visual display of trailer-board indicator action, you just have to enable it by adding 1 to the coding of the onboard supply control unit, using VCDS. This is what it looks like (on my Polo) once you do this (and have a non-LED lighting board connected): 20220930_090155.mp4

Could potentially rule in/out the EGR cooler by bypassing it temporarily so coolant flow doesn't go through it.

You don't even need a bypass relay. Will explain a little later today.

I believe I have read reports of that being fixed by replacing the main ECU relay (#1 in e-box). You said in your first post that the relays had been checked, but I think it would be good to try another relay in that position. Is there another with the same number on the top of it that you could swap from another position?

Did you make notes of what the errors were?

A good example of why everyone with any interest in their car should know their engine code. Makes it easy to look at relevant parts diagrams. See link in my signature (view on computer, not phone) if you don't know what an engine code is or how to find it.

No.

Last time I made a similar knob-up it was the other way round, tried to measure volts straight across the battery with the meter probe in the 20A current socket. Big phut! Fuse inside the meter and a neighbouring bit of track both blew! 😁

Is it that your red meter cable needs to be in one of the left hand sockets? Top (10A) one recommended initially.

It's a fair point with limited/individual disconnections, but at the level of 'all strip fuses and blade fuses removed from battery fusebox', none of the car's controllers can possibly be awake. The only thing left with any power is the starter motor, as far as I can see.

Get well soon mate. I had my first cold in 2.5 years last week, still not 100%. Again, be very careful if disconnecting the main positive feed to the starter motor, that one is not fused at all, it's direct to the positive battery clamp, so it's the most dangerous one to have waving about loose unless battery negative clamp is off the battery post.

Be very careful if you have the battery connected still when you do this. Although there is a fuse as mentioned above, it's a high rating (150 or 175A) so you'll still get an alarming spark if you short it to anything earthed.

No, that's the starter motor feed. Alternator cable goes to the first of the strip fuses, number 1.

There are a bunch of strip fuses, and some blade fuses in the fuse tray above the battery. The blade fuses hide under a plastic cover. Try those, one by one.

Ah, OK. Polo 6R is a generation newer than what I've ever looked at.

My interpretation of that part of the wiring diagram is that the solid black part shown will be present regardless of A/C or no A/C, but the dotted section from the firewall connector (T11b/9) onward to the HVAC unit (T16c/3)* will not be fitted. I was unaware that there was more than one variety of Climatic system, I've never seen a wiring diagram with more than one. *False assumption about where F268 is. Apparently only present in 'heating only' variants of the system.

Yep, mine has it, including little hidey/storage compartment that I found for the first time this summer. 😁

If that light doesn't come on with ignition, that is further evidence of a problem with the alternator excitation circuit. Search for posts where @RicardoM or others have given info about this circuit. I don't have any wiring diagrams for Felicia, unfortunately.

Disconnect it, turn ignition on, measure voltage at end of wire relative to alternator body/battery negative.

Alternator is not starting up. Check that green wire, it is probably not giving the alternator the 'wake up' current it needs.

It will be hanging from the left chassis leg, just near the bottom corner of the radiator. Follow the wiring back from the fan motor.

On a recent car with battery management module it's a bad idea to remove batteries to charge them, because that added charge will confuse the system by being unaccounted for.

Measure voltage directly at the alternator with engine running. Red meter probe on output connection, black meter probe on alternator body.