I get loads of calls along the lines of “I dropped my car key in the sink / left it in the washing machine”.
My advice is always the same. Get a new car key NOW. Usually the reply is, “I’m going to dry it out and see if it works”. It will. You can even speed the drying process up with fice or a hairdryer, but it won’t work for long.
Don’t think that the reason for drying it is to stop it shorting out or something, and that is the end of the problem. Initially that is exactly what happens, but the damage to your car key is done and irretrievable. The water has soaked the board and it will fail.
The components of the car key are soldered on a small circuit board that is made of compressed cardboard and the water has made it swell a little, and become weakened. Over the next few weeks, every time you press a button, the board will flex, and very soon, the delicate solder spots and the very fine copper wires that make the connections will break.
If you are lucky, the car will still start, but the remote will pack up. If you are unlucky, the lot will stop working. Either way, you could be in expensive trouble.
Some cars NEED a working key available to make a new one. If they do, you are left going to the dealer and paying recovery fees, whatever they choose to charge for a new key, and up to 4 weeks of getting a bus or a taxi everywhere.
Even if a new car key can be made without a working key available, the locksmith will charge you more as he needs specialist tools and equipment, and more time, to work out all the codes needed.
So, compare a newer (for instance) Ford. A new car key where there is a working key available, may be around £200.
No key available?
Recovery costs to the dealer. 4 weeks without a car. £4-500 for the key supplying and programming. Never mind that you are stuck with the kids at the seaside, no working car, 70 miles from home and work next morning.
Is it really worth the risk?