Citroen XM Forum

Dieselman wrote: Sun Jul 09, 2023 6:52 am

citroenxm wrote: Sat Jul 08, 2023 11:45 am

The hydractive light flickers on with it too

Either there is crosstalk in the wiring loom (unlikely), or the hydractive Ecu is faulty.

I have an h3 Ecu that works perfectly, though randomly brings on the warning lamp, from either just flickering all the way to full on.
It would be worth checking for water ingress into the connectors and Ecu case.

That car also had a very burned out oil level gauge electrical circuit.
I suspect at some stage, a reverse polarity jump start had damaged both circuits.

I note your car has had an exchange instruments cluster.

If people want to avoid the risk of reverse polarity jump starts don't connect the Gnd jump lead to the battery.
Connect the +12v to the battery and the Gnd to the engine, that way if the positive jump lead is connected to the Battery negative terminal, the negative jump lead will also only connect to the same point.
There will be a large spark and the possibility of the jump leads/battery Gnd strap melting, but it won't damage the car electronics.

Jump leads should connect both the flat and charged batteries in parallel...positive to positive, negative to negative.

Some people are confused and believe the batteries should be connected in series, much like putting batteries into a torch.