2014 XC60 - Alternator Voltage Testing? CTEK Wired Wrong?

[H1cks1]

Hi Team, WOW am I glad I found this forum!

Following house rules: Specs & Stats:

2014 2.0D XC60 R Lux Nav
63K on clocks

New batteries fitted less than a month ago.
Bosch S5 Main Battery
Varta AGM Aux Battery

ISSUE: I believe my Alternator is faulty. I am using a Ctek MXS 5.0 with the indicator quick connector lead attached to the battery. With a healthy battery connected and a working charging circuit I would expect the traffic light to consistently be green. However, every time I check the washer fluid etc the indicator light is orange, on an odd occasion even red. This has led me to believe the Alternator is not charging the batteries enough.

NO Warning Lights on the dash.

Before the battery exchange, we used to find the infotainment screen would intermittently not turn on, stop start rarely kicked in and we have issues with the key fob and central locking.
Since the exchange, start stop is back up and running. No screen issues. Key Fobs do what we ask rarely, volvo DLR checked both keys and said they are not emitting strong enough signal and need replacing.

Voltage Test Values:
Battery Posts 12.66v
Battery Posts (Engine Running) 13.53v
Alternator Post (Engine Running) 13.6v

Question: Are these values low? I have run multiple searches on the forum and most people state I should be seeing 14-14.6v?
I have kept the probes attached whilst the Mrs revs the engine. The voltage does not increase much past 13.55 at the battery, I do not get 14v at the battery or alternator revving the engine.
I have tested the voltages across the battery and alternator and different ground points like the engine, chassis etc. Voltages are all very similar.

Thoughts: I read that it could be a voltage regulator issue. Rather than the Alternator itself. At the time of this post (6/2/24) eBay has reconditioned exchange deals for £139 (genuine volvo part). Considering the car is 10 years old. Happy to replace and exchange for this.

CTEK MXS 5.0 - I am concerned I have installed this correctly. I may also be getting confused with the newer 2017+ models. There is talk of 'under bonnet' charging points. The MXS 5.0 quick connect 'neutral' lead should be connected to the chassis? In my case, I have connected by pos lead to the pos battery terminal, and the neg lead to the neg battery terminal. I am now aware there is a BMS system on the neutral cable and I could be creating an issue with the system not being able to monitor the current correctly? I also found that the main battery and aux battery are connected together, so charging from the main battery terminals charges both?

I hope someone may be able to point me in the right direction?

Cheers in advance all!

[GMcL]

Negative lead should be to the chassis or good earth point not the -'ve post on the battery.

This applies not only to Volvo cars.

The CTEK manual has this in writing then it has a diagram showing the -'ve lead connected directly to the battery. How to confuse the customer...

[H1cks1]

Legendary response speed. Thanks GMcL.

I will rectify this tomorrow, charge back up and do a BMS reset just to be safe.

I wonder if this could be contributing to my issues? If the BMS can't detect the current and flows correctly it may not be instructing the regulator correctly and not pushing past 13.6v when running?