No, you should not turn off the engine of the donor car when jump-starting another vehicle in the UAE. Keeping the engine running is critical for a stable and sufficient electrical charge. When the donor car's engine is off, its battery alone must supply the massive current needed to crank the stalled engine, which can deeply drain or damage both batteries. With the engine running, the alternator actively generates power, stabilizing the system voltage around 14 volts and preventing dangerous voltage spikes that can fry sensitive electronics like the Engine Control Unit (ECU), a common and costly issue in modern GCC-spec vehicles. The UAE's extreme summer temperatures, often exceeding 45°C, already stress batteries; a proper jump-start procedure minimizes further risk.
For a typical 2023 Toyota Land Cruiser with a V6 engine jump-starting a similar vehicle, the power demand is significant. The key is to ensure a stable voltage supply from the donor vehicle's charging system, not just its battery.
- Critical Safety Practice: MOI UAE (Ministry of Interior) vehicle safety guidelines for 2023 implicitly advise this by emphasizing the need for a stable power source during roadside assistance to prevent electrical fires.
- Voltage Stability: RTA Dubai's general vehicle maintenance recommendations highlight the importance of protecting onboard computer systems from voltage irregularities, which is a direct risk if the donor engine is off.
The financial logic is clear: Replacing an ECU in a common UAE model like a Nissan Patrol can cost over 2,500 AED, while repairing damage from a reversed connection (more likely with unstable power) can run much higher. A simple, correct procedure of keeping the donor engine running at idle protects this investment. After connecting the cables correctly (positive to positive, then donor's negative to a bare metal ground on the stalled car), start the disabled vehicle. Once started, let both engines run for several minutes, with the newly-started car's revs slightly elevated (around 1500 rpm), to allow its alternator to begin recharging its own battery before disconnecting the cables in reverse order.
