Battery was replaced but still no power

Some cars/trucks/SUVs need about 30 miles of driving time to load all the new parts you replaced info into ecu so somtimes runs rough until that process is clear . Also there are different ways to reset your cars computer . The best way I found to be really effective is disconnecting both battery cables and connect a jumper wire between them . But make sure they are clear or the battery of course . Leave the jumper connected for a few minutes then hook em back up and start your engine and go drive around for 20 minutes . Another way is to disconnect the POS. battery cable and turn everything on inside while holding the brake pedal. What it is by doing all this is draining the stored power in the computers capacitors that keep the memory fresh . You want it to forget the defective part and recognize the new one .hope this helps you I know how frustrating these things can be.

Check the bulb ground connection. Power may be reaching the bulbs but you need a ground to complete the circuit.

Unhook battery, press brakes to de-power everything. Leave unhooked for half hour or more.

Re-connect the battery. Turn key to on position. Do not start the car... just to on. Don't touch the gas pedal at all. Leave for ~10-20min.

Turn key straight to start and start the car. Do not touch the gas pedal. Let idle for ~10min without touching anything.

Turn off car. Restart, drive. It might take a few heat cycles and a bit of driving before the ECU 'learns' everything over again.

Check the display. Ask a helper to step on the brake pedal while you check the lights from the rear. If no lights appear, check the fuse that connects the brake lights. The owners manual will show the location of the fuse box and which fuse is for the brake lights. Pull out the fuse and look at the wire in the central window. If the wire is broken, replace the fuse. Make sure the new fuse is not blown, and carries the same amperage.
Take note of lights that are out, if any are working. The problem may be cured by replacing the bulb in a brake light that's out. A burned out bulb has a broken filament and a dark brown spot on one side. Check the owners manual for bulb type.
Check the circuit if replacement bulbs and fuses do not restore the lights. Find the wiring diagram in the vehicle assembly manual. The circuit for the brake lights runs from the battery to the fuse, to the pedal switch, to a connection plug, to the lights. The circuit has to be checked with a volt tester at all points.
Check the battery power and the light on your volt tester. Turn the ignition key far enough to activate the electrical systems. Turn on the lights to check for battery power. If the battery has power, ues it to check the volt tester. Put the black lead (the ground) from the volt tester on the negative battery terminal. Briefly touch the red tester light on the positive terminal. The light on the volt tester should flash brightly.
Test the wiring to the fuse. Clip the ground wire to solid metal near the fuse. Touch the light tip to both sides of the fuse. Both should light the tester. If neither side lights, the wire between the battery and fuse is bad. If only one side lights, the fuse is blown.
Test the switch and wiring. Touch the light tip of the tester to both terminals on the brake pedal switch without putting any pressure on the pedal. One should carry power and the other should not. When both show power, the switch is stuck and the brake lights are always on. If neither shows power, the wiring between the fuse and the switch is bad. Now check both switch terminals while the pedal is depressed. Both sides should light the tester. If not, the switch is bad.
Check the connection plug. Unplug the connection and refer to the vehicle manual to identify the brake light wire. Touch the tester light on the brake light wire at the inner socket on the battery side. If the tester lights, the power is flowing to this point. If not, the wire between the plug and the pedal switch is bad.
Check the socket. Plug in the connector plug and remove the bulb. Touch the contact inside the socket. If the tester lights, the socket is good. The socket and wire running to the plug should be replaced if the tester doesn't light.
Check the bulb with the ground wire. The bulb must be in its socket. The ground wire running to the socket should be black or brown. Stab the tester through the insulation. If the tester lights, the bulb is good. Replace the bulb if it doesn't light.
Check the ground wire. Remove some of the insulation around the ground wire. Twist one end of the extra wire around the exposed ground wire. Touch the other end to a solid piece of metal. If the brake light comes on, the ground wire is bad.
Best Offer 2013 11 MB SD Connect Compact C4 Star Diagnosis with WiFi

There is a security switch connected to brake pedal switch and shifter interlock. This will need to be replaced.

1. Remove the silencer boot fasteners located around the base of the lower steering shaft from the dash panel so that it may be pushed aside.
2. Remove the brake lamp switch from its mounting bracket.
3. Disconnect the power brake booster input rod (push rod) from the pin on the brake pedal arm.
4. If equipped with power adjustable pedals, remove the adjustable pedal assembly.

Note: Take the proper precautions to protect the carpeting below the heater core from spilled engine coolant and have absorbent toweling readily available to clean up any spills.

1. Remove the heater core tubes.
2. Remove the two screws that secure the heater core mounting plate to the HVAC air distribution
   
   1. If NOT equipped with power adjustable pedals, pull the accelerator pedal upward and push the brake pedal downward for clearance to remove the heater core from the air distribution housing.
   2. Remove the heater core by carefully pulling it straight out of the side of the air distribution housing.
   Installation
   
   
   1. If NOT equipped with power adjustable pedals, pull the accelerator pedal upward and push the brake pedal downward for clearance to install the heater core into the HVAC air distribution housing.
   2. Install the heater core by carefully pushing it straight into the side of the air distribution housing.
   3. Install the two screws that secure the heater core to the air distribution housing. Tighten the screws to 2 Nm ( 17 in lbs ) .
   4. Install the heater core tubes.
   5. If equipped with power adjustable pedals, install the adjustable pedal assembly.
   6. Connect the power brake booster input rod to the pin on the brake pedal arm.
   7. Install a new brake lamp switch.
   8. Install the silencer boot around the base of the lower steering shaft on the dash panel.
   9. Reconnect the negative battery cable.
   10. If the heater core is being replaced, flush the cooling system.
   11. Refill the engine cooling system.
   housing.

1. Remove the silencer boot fasteners located around the base of the lower steering shaft from the dash panel so that it may be pushed aside.
2. Remove the brake lamp switch from its mounting bracket.
3. Disconnect the power brake booster input rod (push rod) from the pin on the brake pedal arm.
4. If equipped with power adjustable pedals, remove the adjustable pedal assembly.

Note: Take the proper precautions to protect the carpeting below the heater core from spilled engine coolant and have absorbent toweling readily available to clean up any spills.

1. Remove the heater core tubes.
2. Remove the two screws that secure the heater core mounting plate to the HVAC air distribution
   
   1. If NOT equipped with power adjustable pedals, pull the accelerator pedal upward and push the brake pedal downward for clearance to remove the heater core from the air distribution housing.
   2. Remove the heater core by carefully pulling it straight out of the side of the air distribution housing.
   Installation
   
   
   1. If NOT equipped with power adjustable pedals, pull the accelerator pedal upward and push the brake pedal downward for clearance to install the heater core into the HVAC air distribution housing.
   2. Install the heater core by carefully pushing it straight into the side of the air distribution housing.
   3. Install the two screws that secure the heater core to the air distribution housing. Tighten the screws to 2 Nm ( 17 in lbs ) .
   4. Install the heater core tubes.
   5. If equipped with power adjustable pedals, install the adjustable pedal assembly.
   6. Connect the power brake booster input rod to the pin on the brake pedal arm.
   7. Install a new brake lamp switch.
   8. Install the silencer boot around the base of the lower steering shaft on the dash panel.
   9. Reconnect the negative battery cable.
   10. If the heater core is being replaced, flush the cooling system.
   11. Refill the engine cooling system.
   housing.

STARTER SELONOID OR DIRTY BATTERY CABLES OR LOOSE CONNECTION ON STARTER.iF YOU REPLACE STARTER REPLACE WITH COMPLETE UNIT NOT JUST SELONID GOOD LUCK.PS BE SURE BATTERY IS UP TURN LIGHTS ON AND HAVE SOMEONE WATCH THEM AS YOU TRY AND START TO BE SURE THEY DON`T GO OUT IF THEY DO--- GO TO CONNECTIONS ON BATTERY OR TRY JUMPING GOOD LUCK

When you turn the ignition key to start your car, voltage from the battery flows through the ignition switch to the Park/Neutral safety switch and/or brake pedal or clutch pedal safety switch (you have to push the pedal down before the circuit will complete) to the starter relay or solenoid. When the relay or solenoid is energized by voltage from the ignition switch circuit, it closes a contact that routes more power from the battery directly to the starter to crank the engine. The starter motor spins, pushes the starter drive gear to engage the flywheel and cranks the engine.

Low battery (Check battery voltage, recharge if low, or jump start with another vehicle or battery charger).
Loose or corroded battery cables (Inspect, clean and tighten BOTH ends of BOTH battery cables).
Bad starter relay wiring connections or ground connection (Inspect, clean, tighten wiring connections).
Bad starter relay/solenoid (Check for voltage at relay, if relay has voltage but there is no "click" when key is turned to start, replace relay).
Bad starter (Jump battery voltage direct to starter to see if it spins, or remove starter and have it bench tested at auto parts store).
Damaged starter drive or teeth on flywheel (Remove starter and inspect drive gear and flywheel teeth, replace damaged parts if necessary).
Bad ignition switch (Check to see if voltage reaches starter relay/solenoid when turn to start. If not, check for open P/N switch and brake or clutch pedal switch. Replace ignition switch if defective).
Open P/N safety switch, or open Brake Pedal Safety Switch (automatic transmission) or open Clutch Pedal Switch (manual transmission). Bypass switch with jumper wire to see if engine cranks, or use test light or voltmeter to check for voltage passing through switch when ignition is turned to start.
Engine seized due to bearing failure or internal damage (Use socket and long handle to see if engine can be turned by hand, if not engine is locked up).
Engine hydrolocked due to coolant leak from leaky head gasket (Use socket and wrench to see if engine rotates, remove spark plugs and see if coolant comes out or engine can not be cranked with plugs out).

Check all battery terminals and 12v power feed connections are clean and tight.
Check all battery chassis and ground connections are also firm and in good order.
Check any in line 'Maxi' fuse connections are firm.
Check for water ingress in any cable loom or bulkhead connector exposed to the water spray.