2005 Lexus LS400 "battery wont hold charge 05" Questions

wont start sometimes The battery will hold a charge but when we try to start the car it wont start most of the time and it drains the battery. Checked the starter and the alternator, they both checked

battery wont hold a charge the alternator tests as good. There is a black box on the back of the alternator that if we pull up on that it charges up the battery but as soon as we let that go the ...

...battery with jump leads my fiesta diesel wont turn over and election windows and central locking wont work what's the problem car is 1.4 tdci 05 plate Car was OK I was warming my van up in the ...