Starting the engine from an auxiliary power source (Audi Q7-4L-D)

Using an auxiliary power source will help start the engine in an emergency, but then you should find out and eliminate the cause of the battery discharge. The most common reasons include:

• Making repeated unsuccessful attempts to start the engine, or leaving the lights on for extended periods of time with the engine not running;
• Malfunction of the charging system (the alternator drive belt is loose or broken, the wiring is damaged, or the alternator itself is faulty);
• Malfunction of the battery itself (the electrolyte level has dropped or the battery's service life has expired).

When starting the engine from an external power source, attention should be paid to observing some special precautions:

• You should not try to start the engine from a frozen battery (a discharged battery can freeze already at 0°C) - warm it up first; subsequent regular use of a thawed battery is not recommended;
• Starting the engine from an auxiliary power source should only be done when the power unit and catalytic converter are cold;
• Jump starting should not be attempted using a battery charger;
• Before connecting the booster battery, make sure the ignition is off;
• Use only cables with sufficient cross-section (not less than 25 mm² for a petrol engine and not less than 35 mm² for a diesel engine) and with insulated terminals, cables must comply with DIN72553;
• Make sure all electricity consumers (lighting and heating devices, windshield wipers, etc.) were also turned off;
• Wear protective gloves and glasses;
• Make sure that the booster battery's output voltage matches the battery installed in the affected vehicle;
• If a battery installed in another vehicle is used as an auxiliary power source, ensure that the vehicles do not touch each other;
• The donor car's engine must be running at idle speed;
• Make sure the transmission is in neutral;
• Remove the ventilation caps from the discharged battery and cover the holes with a rag.

The wiring diagram and sequence are shown in Figure 12. The battery is located under the driver's seat, and in the engine compartment (rear left corner) the terminals of its terminals are located. The positive terminal (1) is covered with a red cover.



Connect the end of one wire (usually red in color) to the positive terminal of the discharged battery. Connect the other end of this wire to the positive terminal of the auxiliary battery.

One end of the second wire (usually black in color) connect to the negative terminal of the auxiliary battery. Connect the other end of the black wire to the special bolt (4 in illustration 12).



Make sure that the connecting wires do not come into contact with moving components in the engine compartments of both vehicles (fan impeller, drive belts, etc.). In a vehicle with a dead battery, turn off the car phone or follow the car phone's operating instructions for this situation.

While maintaining the engine speed of the vehicle with the good battery at 2000 rpm, follow the normal starting procedure for the vehicle with the dead battery, then let it run at high speed for at least three minutes.

Note: Do not allow the starter to operate continuously for more than 10 seconds.

To prevent voltage surges when disconnecting the wires, turn on the rear window defroster and the air conditioning fan. Then, with the engine running, disconnect the wires in the exact reverse order of their connection (see above). Don't forget to reinstall the battery vent caps.