Strange electrical fault today on 2004 Leon Cupra Mk1 150 diesel. On turning the key to start all the dash lights started flashing, the central locking was turning on and off like crazy and the heater fan started going. The car started OK and runs fine, only thing is the airbag warning light is on and wont go off. On another day when starting it the wipers started going full speed and the heater fan also. Checked for codes but nothing apart from the usual EGR warning one (been there for years ! ) Any ideas as to where to start ? some relay fault maybe ? or earthing problem ? Have checked out the earthing point under the battery tray and its OK and the big earth lead that attaches to the engine block looks fine too . Thanks....
Weird electrical fault
- Thread starter skyeten
- Start date
Yes it was, the car usually stays in a garage but was outside for a few nights there, in the past it has had the usual water leaks into footwells but the doors were sealed many years ago and have never had any probs with water getting since. Just removed the under dash panel there to check the relay board, all seemed to be OK but cleaned up a few of the relay terminals anyway. I did find a loose earth when I was in there and fixed that. As soon as I connected the earth lead again on the battery the central locking started working on its own for about 5 times then stopped ! One thing I am thinking now is that there is something wrong with the igniton switch as when you put the key in it does not feel quite right....
Off the top of my head I think it's either 100 or 109 mate. You can pull it out and apply 12v across the coil, then use a multimeter to check continuity across the load pins. Maybe check the socket that it plugs into for corrosion while you're there. One word of warning though, that relay panel has some high current going to it, with the only protection between you and the battery being a 110amp fuse. If you need to clean the terminals then make sure to disconect the battery first.
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