Gremlins

moltuae · #1 12th February 2019, 09:04 PM

Possibly a stupid suggestion, since I know nothing about D3s, but could a bad main earthing point be the cause?

Audidothat · #2 13th February 2019, 06:46 PM

Actually I think you might be on to something. I wonder if there is a test for that?

MikkiJayne · #3 13th February 2019, 07:03 PM

Battery terminals ok? I had a D2 do something similar when the positive terminal was loose. That blew up the alternator though.

How about that bolted terminal in the footwell that's problematic? Does it have a main power cable feeding in to the electrics box in the passenger side like D2s do?

I'm not sure how you would test for a bad earth. The modules likely wouldn't be able to detect it since they would power down for a moment. There should be a main earth from the battery negative, but I'm not sure how thats done in the D3 with the battery module.

I'd also be searching for the main harness earthing points which are usually under the dash on the A pillars.

It does have a hint of 'nibbled' wiring harness though too.

Very odd.

Ameiseuk · #4 14th February 2019, 04:20 AM

Could the oil leak have caused some damage to the alternator?

I've seen electrical gremlins manifest themselves through a voltage spike coming from a faulty alternator - a generic OBD reader with the ability to track voltage should be able to map what the alternator is doing.
Plug it in and take the car for a good drive and review the results.

A good clean up of heavy pos and neg terminals would also be a cheap fix if it cures the problem.

Audidothat · #5 15th February 2019, 02:54 PM

Leaking battery - I took the battery out and everything underneath is covered in a light film of battery juice, lots of yellowing and corrosion. The corner of the boot closest to the battery was dampish. The outside of the battery was wet.

Please see photos. Any ideas what those modules are? I have disconnected and checked, visually they look ok.

Do we think I have found the culprit?

I hope this is going to be ok.

snapdragon · #6 15th February 2019, 03:01 PM

Wow, never seen that before. I would put sodium bicarbonate all over it to neutralise it. Does the battery have that 5mm hole in the end that that pipe plugs into like the original? Did it come out?
Do you think it boiled up or is it cracked?

MikkiJayne · #7 15th February 2019, 03:17 PM

If it has boiled that is indicative of a dodgy alternator regulator. Have you checked the voltage when its running? It should be 14.4 max at the alternator output. Usually that's about 13.8-14.0 by the time it gets to the battery.

I'd expect the battery monitor on the D3 would log a fault for this though so it may simply be physical damage.

Audidothat · #8 15th February 2019, 03:17 PM

Yes to the hole and the black pipe was connected. It doesn’t looked like it has split or cracked anywhere so perhaps as you say, it boiled up!

What I can’t figure out is whether a crazy battery would cause all the electrical glitching? Anyway, at the very least I have to get a new battery so here’s hoping!!