1997 Ford F-250 heat

1997 FORD F-250
130,000 MILES • 5.8L • V8 • 4WD • MANUAL
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COUNTRYBOY3490
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  • 2 POSTS
Yes my heater isnt blowing hot air like it should. I have flushed the heater core twice and changed the thermostat. When the defrost is on it blows lukewarm air. When i switch it to vent the air is hot then switches to warm air. And will switch to defrost on its own. When i switch the heat sources there is a bit of a delay. I was wondering what is causing this. Is the heater in the dash clogged with something or is there a bad relay somewhere?
Jan 22, 2014 at 9:05 PM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,240 POSTS
Are both heater core hoses getting hot? Have you checked for vacuum leaks in the vent door system? Have you checked the blend air door for operation?
Jan 22, 2014 at 9:38 PM
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COUNTRYBOY3490
  • MEMBER
  • 2 POSTS
Yes both heater core hoses are getting hotlike they should. The temperature control door
seem to be working fine. No vacuum leaks that i know of. Although my truck leaks a little antifreeze from somewhere. And its only a few drops here and there.
Jan 22, 2014 at 10:29 PM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,240 POSTS
If both heater core hoses are hot, then you have to have a problem with the blend air door. The idea that blower direction changes from the defroster to vent by itself leads me to believe there is a vacuum leak.
Jan 23, 2014 at 12:47 AM
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