In diesel vehicles, a pigtail-shaped light indicates that the are heating the cylinder heads before starting, usually lasting 30 seconds or less.
Are you asking about a or an external heater (like a block heater)? PREHEAT ENGINE
Generally recommended when temperatures drop below 10°F–20°F (-12°C to -7°C). In diesel vehicles, a pigtail-shaped light indicates that
To give you the most relevant information, could you tell me: Is this for a or an aircraft ? To give you the most relevant information, could
I can help clarify what "Preheat Engine" means for your specific situation. Should I preheat my Tiffin Bus 450 DP engine? - Facebook
Prevents oil congealing, reduces internal engine wear from cold-start oil starvation, and ensures easier starting.
"PREHEAT ENGINE" refers to the process of warming an engine's internal components and fluids (oil and/or coolant) before starting it in cold weather, usually at or below 20°F (-7°C), to reduce wear and ensure a successful start.