After changing dead battery, the blower will not work.

Mercedes-Benz M-Class ML 350
no YEAR told .
the service manual covers this.
or check all fuses.
the users guide may cover it of chapter fuse,,lost it?

non in USA< so no books to read to you from here.
fuses are first we check them all.
and in USA we can scan the car OBD2 AND it MAY SHOW WHY.>?
blower dead , as in silent even on high.?????
try high speed mode blower first, if that works and lower speeds not the resistor block is bad. if all speeds dead , see below.
is this car manual controls or climate controls
the later uses no resistor block it uses powerful controller..
bad blower, or bad controls.
the resistor block if present at all, is on the output casing the blower
as the resistor gets super hot so is cooled by the blower air flow.

the blower can be hot wire tested in place.
it has only 2pins, one is ground other is 12vdc.
so we hot wire it using 15amp fuse jumper and yell, see it is good easy.
now know input to blower is dead.
we discover if manual or climate controls are here and I can not do this in USA<

sad is you not saying what does work, see why?
making this 10x harder,

4 possibles. not one is crank sensor, SORRY!

check head lights first and dash heater blower on high first.????

1. battery dead if head lights dead. and blower key on.
2. fuses blown , check all fuses if no schematic, in hand.
3. bad power distribution main box to the , cab box
4. ignition switch bad or relays related, gee, cant guess, as headlights never mentioned. (hot all times too and separate path of power)

charge/battery/alternator lamp on is top clue
4wd, ill ignore.
you meant Hvac blower dead.? right, dash blower? same blower for heat and a/c so......???????
that to means blown fuse, or battery went DOA.
battery volts is 12.6v charged. and rested
running its 13.3vdc to 15v if not the alternator is OFFLINE.

with a voltmeter this is 5min work, with out days.? guessing?
ill do why> notparts
battery dead. (or discharged. the charge lamps comes out for alternator dead, due to many reasons, engine stalled,? low engine rpm, 400 is too slow, fan belt fell off or slips.
fuse blown. check fuse?
any were, related to alternator, and battery are suspect if alternator rpm is good.

no guessing here, that be silly, i use the voltmeter 1st.
12vdc across all fuses in all boxes, on both sides of fuse key on
got that?

Check fuses in fuse boxes, posible blown fuse. what kind of car?

(1) possible blown fuse.
Note that fuses blow for a reason - seek out the reason, or it will blow its new fuse too.

The main fuse block is located inside the left side of the engine compartment near the battery. There is also an interior fuse panel located just above the left side kick panel.

Interior Fuse Panel
The interior fuses simply unplug from the fuse panel. Use the fuse puller tool provided with your car to remove fuses from the panel. The tool is located on the back of the interior fuse panel cover.


(2) possible blower motor dead. See maintenance manual excerpt below.

(3) possible blower motor relay faulty. Location of Blower relay:
Under hood, drivers side, front engine area,rear of headlight housing; relay mounted on drivers side of radiator shroud.


1990-92 Mazda 626 and MX-6
See Figure below

1. Disconnect the negative battery cable.
2. Remove the glove box and the underdash cover.
3. Detach the electrical connectors from the blower unit.
4. Remove the blower unit-to-fire wall attaching bolts and remove the blower unit assembly.
5. Remove the blower motor fan-to-motor fastener.
6. Remove the blower motor-to-unit attaching bolts, then remove the motor.
7. Installation is the reverse of the removal procedure.

If you vehicle has the automatic temperature control system, where you can set the desired temperature using the digital temperature readout, then you most likely have a failing blower motor speed control module. This is an electronic module the controls the blower on/off and speed operations and when it fails it often won't shut off the blower when you shut off the vehicle which can result in a dead battery if you don't pull the power supply fuse. Its a small rectangular box located under the right side of the dash [passenger side] by the blower motor and isn't to hard to change. Hope this helps and good luck!

check the blower motor relay, located under the hood fuse/relay box. turn the system on and tap the blower motor see it works. The blower motor located under the glove box.

it's either a fuse or it's a bad blower motor, it could be a bad blower motor resistor but usually you'll get either high or low only, so if you have nothing on any speed, high low etc, and all the fuses are ok chances are it's your blower motor.

I had the same dead blower problem, the resistor was corroded. It´s under the dashboard on the passenger side.