I have a 2005 Zafira A, 16v 1.6 petrol.

A couple of weeks ago the gauges on the dashboard started dropping to zero for a second or two whilst driving. ABS light would also come on at this point. Engine would carry on fine. It seemed - although I can't be certain - that it was most likely to occur just after some kind of bump or pothole.

A couple of days later this escalated to losing the radio code overnight. At this point I thought it was probably battery and/or alternator. I had trouble starting a few times as well, although I did always get it going in the end.

Things got worse and the other day I had the engine cut out entirely and all electrics stopped - dashboard went completely blank, lights out, couldn't put hazards on or anything. Thankfully I was still on the driveway at the time, but obviously I'm not driving the car at this point. I swapped the battery out with a known good one and got the same behaviour.

When the engine cut out, I had the alternator, emissions and oil pressure lights come on solid (but no immobiliser light) and stay on with key out the ignition. Disconnecting battery and reconnecting it added the immobiliser light until I disconnected things for longer. After leaving things for a few hours, I reconnected battery and car started fine, no lights. Again, it died after a little while.

I've since borrowed a multimeter and both old and new batteries were fine, and alternator was giving about 14.2V at idle with nothing on and about 13.6V at idle with headlights, heaters, demisters etc at max - so I don't think it's charging related.

I did a bit more investigating and found that the fuses within the under bonnet fuse box were damp. Oh yeah and the cover isn't clipping on properly the neighbouring relay box is no longer attached with a bracket but is cable tied on... I hadn't noticed this before, but the backstory to that is 6 months ago I had a new steering rack fitted as the old one was leaking and in the process of changing it the garage killed the pump and had to get a new one. I have a recollection of them saying it was one with 2 wires instead of 3 like the one I had before, so they needed to adapt the wiring harness or something along those lines. This in all likelihood is when things mysteriously changed.

So at this point I think I need to take the car to an auto-electrician. Can anybody think of anything else I can check or attempt to rule out before I do?