Battery drain issue

[Alex10391]

Hi all, have a frustrating issue with my Chimaera that’s come on only in the last couple of months.

In March, I couldn’t get into the car as the battery had gone low to the point of not being able to open the doors. I subsequently had a new battery fitted after the AA pronounced that one dead.

A few months later and after only a week of being on holiday (and with regular use before) I returned to find the car completely dead again. AA came out and managed to boost it up but clearly there is a drain issue.

This could be complete coincidence but the timings make me wonder - shortly before the first flat battery in March, it had been to a specialist who fitted a relay to the immobiliser, to address an occasional “hot starting issue”.

Bear in mind I’ve owned the car since October and had no issues with the battery until then. Pretty much since and oddly with the car getting much more use , it’s ran two batteries completely flat. I could be way off here but could it be related to the extra relay fitted?

The AA have managed to boost it up and now it’s sat on trickle charge to hopefully hold. When opening the doors, randomly the hazard lights have come on.

Think next step I think will be to have an auto electrician out, any places you would suggest to start looking?

Thanks, Alex

[sixor8]

Have you tried grabbing hold of the relays down by battery without the key in the into see if any of them are warm?

The commonest problem is one of the 2 fuel/ ECU relays being replaced with the wrong type. The AA replaced one on my '95 Chimaera back in 2002, and it flattened the battery. The wrong type (single or double pole, you'd need to check which, I'm not sure) provide a current path through to the O2 sensor heaters when re-energised.

[PabloGee]

Definitely worth feeling for a warm relay - I had one that was a hot start kit that had been wired incorrectly by the previous owner. It was constantly energised, and meant I had a 10 day window of battery power.

I eventually rewired the starter circuits, and changed that relay out for a bigger better one, and wired it correctly, and now I can leave my car without being on charge at all. I tend to drive it once a week, but not always.

The other known culprit is the interior light delay relay on the fuseboard, it fails and drains the battery. If you still have this fitted, you could try the short on that circuit:

https://www.bertram-hill.com/courtesy-light.html

[Belle427]

Its worth doing a parasitic drain test, you can pull relays etc and see what affects it.
A cheap multimeter from screwfix etc is all you need.

[PabloGee]

Good shout.
Certainly worth investigating the new relay feature too