Took my Sportrak (1995, 82,000 miles) off-roading last sunday, and whilst jet washing it all over at a garage, the passengers in the car were listening to the radio for about 10-20 mins. Came to start the car and completely dead, completely flat battery. Slowly came back to life a little while waiting for help, but not enough to start. Started fine with a jumpstart on the battery.
Started ok all week, until yesterday, again waiting for a jet wash, I had the radio on (engine off), as I've done many times, for about 5 mins, and again, not enough power to start. Left it while I washed the car down and 15-20 mins later it had recovered enough to start the engine.
This morning it will also start ok.
First thought is the battery is a bit knackered, maybe time for a new one? (not sure how old it is).
Second thought is maybe its something to do with a bad earth??
Anyone any ideas or comments/suggestions?? Could it be the earth, and if so where should I check it??
Thanks in advance,