I hope everyone is well amongst the chaos of the Covid Crisis. My car (Mondial T 1990) has suffered a dead battery due to lack of use since the lockdown began so I took on the project of changing it last weekend. That seemed to okay once the wheel was off and I was able to get into the wheel arch. The car now starts on the button and the engine runs just fine. However, I've now got some weird behaviour with the electrics that I need on advice with please. The following ancillary functions have now stopped working (completely, i.e. no relays clicking or any other behaviour). The central locking, windows, radio, lights, boot release and lights have all ceased working. Even the hazard warning flashers have stopped working. However, the immobiliser, front trunk, wipers, indicators and air conditioning are all working fine. It's a bit of a head scratcher, NONE of the fuses have blown and I've clean the battery terminals to try and make sure that it wasn't just a bad earth but to no avail. Any idea what might be causing this please? Thanks
Odd one, electrical contacts of the ignition switch ie position 1 lights position 2 headlights position 3 start? Bit of a guess. Jim Sent from my SM-T510 using Tapatalk
There are two fairly large red cables that bring +12V power from the battery to the fuse-relay panel. First thing to do is just unplug/inspect/reseat the connector for those cables (it has two large spade connectors). Your WSM schematic shows that there is a sort of junction block (near the battery I think) connected to the + terminal of the battery by one really big red cable where these two fairly large red cables originate -- probably come bolted connections there that you can check for cleanliness and tightness.
Make sure to check the overall health of the battery as well. Sometimes fully discharged batteries can become less then optimum and cause all sorts of electrical gremlins.