Hi guys,

I bought a 2.0 litre sonata recently, and it's registered offroad until the end of the month. I've been starting it up every few days and leaving it on just to keep the battery vaguely topped up, but I cam to it the other day and it had run completely flat, not even the immobiliser LED worked any more. After charging it with a mains adapter on trickle for 2 days, I plugged the battery back in, and the radiator fan came on straight away, and basically won't stop. I'm not sure what to do, i've read this post on t'net

http://www.forparts.com/techsonata.htm

Which seems to indicate that it could be corrosion in some of te wiring, not sure where I can find the diode that it mentions though. The engine still starts fine, the radiator fan runs the whole time, before during and afterwards

_Update_

I've literally just had a friend come over and have a look at it since i wrote that last few paragraphs. he's unplugged the temperature sensor relay/connector and basically, it seems like it's that causing the problem. I'm going to wd40 it in a short while and then clean the contacts... that might sort it... i'll update you guys if it works... if not, mnight have to get a new temperature sensor. Basically, the thing unplugged is a green connector right in the middle underneath the fans. You can reach it from underneath the car.

There ya go, could be problem and solution in one post