Electric issues and earth points

[tommad]

Hi,

I posted last month about a start-up problem with my 4.0l AJ6 facelift, which may related to the oxygen/lambda sensor. It is currently OK, but I am planning to get these checked properly. However, I mentioned a problem I had in the run up to this, which I though was related but now am not so sure.
The issue was that whilst driving there was occasional odd sensation of very brief power loss, when also battery power seemed to dip and steering/brakes seemed very heavy, but only for a couple of seconds and several warning lights would come on briefly (all happens too quickly to really note what exactly). However, a couple of times more recently it has been a little more serious and had to restart the ignition (quite disconcerting when driving).

Really not sure what the problem is, a bit of reading mentioned the earthing points but really not sure where these are on my car. Does anyone have a thoughts as to what might be the issue?

Thanks,

Tom

[PaulGover]

Steering heavy implies the drive belt to the pump has stopped moving, or the engine's stalled. Brakes suddenly appearing heavy implies a power cut to the brake ECU. This is more than just earthing points, as it's car-wide. It seems as though you're losing power to one of the major circuits, probably the one for all devices attached via the ignition switch. That it's hitting everything at once and then recovering completely, rather than a gradually increasing set of failures suggests it's not a bad connection (such as an earth fault), more something like a faulty relay. That said, I don't know the wiring on the 4.0l models, so I can't say if there's a relay connecting the ignition switch circuit, but if there is, I'd look at it and the circuit powering it.

[tommad]

Thanks Paul,

Yes, I am coming to a similar conclusion. It's happened a few more times now and getting a better understanding on what's going on. When I hit the clutch, occasionally the revs seem to drop right down. Sometimes they bounce back up after a second, but other times the engine stalls. It does this very quietly (almost imperceptibly) without any sputtering/juddering etc and so it's not even obvious that it has stalled.

Sadly, this is beyond me and I think it needs a trip to the garage...