Hi all,

I have a 2018 Volkswagen Golf Mk7.5 (28,900 miles) that had no warning lights or electrical issues at all.

I took it to Halfords (Walsall, UK) for a preventative EFB battery replacement because the original battery is \~8 years old.

As soon as the new battery was connected:

	• The horn started blaring

	• The dash lit up with multiple errors

Faults now showing include:

	• Start/Stop error

	• Hill Hold Assist error

	• Front Assist unavailable

	• Tyre pressure monitoring unavailable

	• Red steering wheel warning

They tried coding the battery but said their diagnostic tool was playing up. Then they managed to do it using a ‘different’ diagnostic tool. After a short drive they said the power steering stopped working completely and the steering became extremely heavy.

They now claim:

	• Engine bay fuse box / power distribution panel is blown

	• Alternator fault

The car arrived with zero faults, and this all happened immediately after they connected the battery.

The RAC also checked it and said there’s inconsistent power at the fuse box and the alternator isn’t charging. The car had to be towed home.

The Halfords Autocentre say it’s just coincidence and deny responsibility, they are adamant that there was an underlying issue with my alternator. I did raise a comprehensive complaint with ‘Head office’ and provided a full timeline of events. I wonder what they’ll actually do. 

Has anyone seen something like this happen before? Should I get a diagnosis from Volkswagen and then try to claim the repair cost back from Halfords? To be clear, The car had no fault codes or warning lights before the battery change and the issues started immediately when the new battery was connected.

Thanks for reading and I’d appreciate any advice given. 

Battery replacement caused multiple faults