Chasing the common no heat problem.
Grand Champion
Joined: Feb 2015
Posts: 7,435
Likes: 578
Pump pushes flow threw the heater core constantly, So if there is air in it it will get flushed out.
The ac compressor comes on when using defrost so you will notice a temp change.
If you are getting air flow threw it you should notice a difference with the heat on full blast. I think your issue is the heater core. Did this issue just start? If the engine is at operating temp you should get heat from the core unless it's clogged. When i bought my truck the dealer put in stop leak rather than fix the leaking freeze plug. It clogged both the core and radiator.
I get warm air from the vents when it's on vent. If it's on defrost it's not as warm. I assume this is partially due to cold air leaking around the blend door, since the defrost setting turns on the compressor. This would not explain why I don't get HOT air from just vent.
Both sides of the heater core get very hot to the touch
Administrator
Joined: Apr 2010
Posts: 87,362
Likes: 4,209
From: Clayton MI
Pump pushes flow threw the heater core constantly, So if there is air in it it will get flushed out.
The ac compressor comes on when using defrost so you will notice a temp change.
If you are getting air flow threw it you should notice a difference with the heat on full blast. I think your issue is the heater core. Did this issue just start? If the engine is at operating temp you should get heat from the core unless it's clogged. When i bought my truck the dealer put in stop leak rather than fix the leaking freeze plug. It clogged both the core and radiator.
The ac compressor comes on when using defrost so you will notice a temp change.
If you are getting air flow threw it you should notice a difference with the heat on full blast. I think your issue is the heater core. Did this issue just start? If the engine is at operating temp you should get heat from the core unless it's clogged. When i bought my truck the dealer put in stop leak rather than fix the leaking freeze plug. It clogged both the core and radiator.
