Yesterday I went to start my 2003 ML500 (108,000 miles) and it would not start, sounded like a low battery, so I got a jump and it started right up. I went two blocks and it just died and would not start even if I jumped it. I got it towed home and then about 3 hours later it started up. I took the positive battery cable off and it kept running..........

could it be that I have a bad battery?


Thanks
Cooper

 

Hi Cooper, first of all, you should never remove positive cable from the battery first! Always remove the negative ccable first.
When it dosn't start, is the engine cranking good without firing, or you can hear click but the engine dosn't turn over?
If your existing battery is turning the engine over fine but it's not starting, you should check or replace your CPS crankshaft position sensor.
If it hardly turns over the engine, it is time to put it on charger or replace it with new battery (it depends on age and ability to hold capacity). Any auto parts store will test your old battery for free.
Just replaced my ML battery three days ago (7 years old Duralast with 3 years old OEM).
Good luck,
Bernard

 

When I first tried to start it would crank and not start............. then when I got it started it drove for about 2 blocks and died..............

would the CPS cause it to die for no other reason?

thanks for your help

Mike