2002 ML500 will randomly not start. Battery check
are the battery terms clean, this is a service point.
will it not crank or not start, your no start makes no sense.
no car can start if it cant crank, so..... (i can push start mine,with stick shift tranny)
random sux. it's the most expensive word in the eng. language.
ILL pretend you meant ,IT WILL NOT CRANK.
well we do know 4 things and that is
1: the battery can bad, why not use a substituted, (#1 all time failure rate on all cars since 1920 to now, ) barrow one.
2: it has bad connections.
3 bad starter or soleniod.
4: bad key line (small wire on solenoid running back...all can fail)
you can guess, and go broke, or do that tests.
it is your choice, all time record forums is
the other things dead means the connections are bad.
called Main power DC distrutution.
did the windows fail , key on, or only cranking.
ill guess at only key on. they fail. (key point that)
in fact I alway fix power loss to the most basic simple devices.
#1 is head lights fail or dim with fan/and defrost (year) on.
i load up the bus and see if my HL have full brightness.
the fan , is it weak., with all major loads on>?
I fix that first.
and is childs play simple using any voltmeter 20v.
you go to the battery, and across it its 12.6v rested at bat. lugs!
you then turn on fan,defrost and HL.
the battery can do 2 things.
1: say above 12v.
2: drop way low, say below 11v.
if the battery drops its bad, (cranking can in fact drop a battery to 10 or if in alaska 9v)
but if the lamps dim and the batter is 12v
you have bad wiring, no ifs, ands or buts.
ok the wiring is bad, move the red lead down stream from
the bat, PLUS lug, to the fuse Engine bad fuse box.
this is MAIN box. it must have 12v with loads stated.
what i do with schematic in hand is follow that path
the whole way to the head lights.
The stater will not engage if the key line does not go to 12v
10 -18v is the spec on all cars. running.
the starter solinoid coil dies, at 8v,and starts clatttering.
ok lets say the HL are full bright under full loads.
A/T tranny on MB no sticks id bet. (transmission = tranny)
wiggle the brake pedal, the gear shift in park, does it crank>? now
or try starting in Neutral, (this picks off fresh brass in the PRNL switch (yes, ive cleaned many) and does it crank now?
no , then take a small hammer and hit the side of the starter
does it crank now.?
a mech,does all this, with out thinking,its, same o, same o.
then i hot wire the starter soleniod
crank now? (bad key line)
no?, bad starter, bad battery or bad cables. (in truth?, i do this first ,no crank, if terminal on battery are clean.)
if i walk up to battery and it reads 10v, a cell is open.
(or is grossly discharged)
i also have a huge inductive amp clamp meter, (they are cheap today) and check starter current. 100amps is a hot day 1.6L cars
and up to 500 amps on a big engine in Alaska. dead winter.
if the current goes to (tries) to infinity the starter is shorted.
or jammed the engine is seized.
only 2 tools, a volt meter and an ammeter and the truth be known.
on Nov 11, 2013