Having problems with your 1999 Chevrolet Silverado 1500 ?
Heater not working right in 1999 silverado. Blower works fine,not over heating, blows cool air when idling blows warm air when moving.
First check the coolant level if the engine is hot check the reserve jug on the firewall--if cold before start up remove the radiator cap and check coolant level add as needed. If the thermostat has been removed it needs to re-installed. It is possible that the heater hose(s) is stopped up. After letting it run for a period of time both heater hoses should be hot to the touch if they aren't something is restricting the flow of coolant the system needs to be drained and flushed. I have also see some vehicles form an air lock in the coolant system causing the same thing. It then needs to be (burped). This can be checked/done by removing the radiator cap while the vehicle is idleing and watching the water level in the radiator squeeze the upper radiator hose to see if the water/coolant level rises in the radiator. When you release the hose you may need to add some coolant this forces out the air. Hope one of these things. These are some of the cheapest fixes and if they don't work/help then you need to start looking at the heat control selector.
Repair Help & Product Troubleshooting for 1999 Chevrolet Silverado 1500
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