Ford Ranger 2007 Wildtrak, Manual 3.0l, diesel 12000 miles
Truck developed a starting issue after a fix on the nozzles. The heater plug sign won't appear on the dashboard until several attempts. It is worst after running and when it's hot/warm weather. Problem is getting worse now with over 40mins wait before engine starts
Low coolant level: If your coolant level is low, this can affect the flow of coolant through the engine and the heater core, causing the air being blown out of the heater to be cold. Check the coolant level in the radiator and the overflow tank to make sure that it is at the correct level. If it is low, add more coolant.
Blocked heater core: If the heater core is blocked, it can prevent hot coolant from flowing through it, resulting in cold air being blown into the cabin. A visual inspection of the heater core hoses and the core itself can help you determine if it is blocked. If it is, you'll need to have it replaced.
Faulty thermostat: A faulty thermostat can cause the engine to run too cold, which can result in cold air being blown through the heater. You can test the thermostat by feeling the upper radiator hose. If it is hot, the thermostat is probably functioning correctly. If it is cold, the thermostat may need to be replaced.
Faulty water pump: If the water pump is not functioning correctly, it can prevent hot coolant from being circulated through the engine and the heater core, causing the air being blown out of the heater to be cold. You can test the water pump by checking the drive belt for tension and the pulley for any signs of wear or damage.
Blocked air ducts: If the air ducts are blocked, they can prevent warm air from reaching the cabin. This can be due to a clogged air filter or other debris blocking the ducts. Check the air filter and the ducts to make sure that they are clear.