Heat doesn’t stay hot!?

[Bradford]

Hello everyone.

Working on my 2005 Ram 2500 Heavy Duty Hemi. When the heat is first turned on after the truck warms up i get a blast of nice hot air and then after about 3 seconds turns to cold. If i turn the blower off wait about 15-20 seconds do it again another blast of hot air…

Blower works(obviously) core is heating up, Blend doors are working properly because if i switch to cold, the air gets very cold and then when i switch back to warm it gets hot for a second or two and back to barely warm air.

Where is the hot air going!!!???

Thanks for you help in advance!

Topic

[college man]

check that your coolant is full. If you have a scan tool read
live data coolant temp to see if the actual temp is correct.
If coolant is full sounds like the t-stat is stuck open or not
working correctly. Has any coolant system work been done?

[Bradford]

Hello college man,

Coolant is full, T-stat is only about 6-8 months old. Truck gets to temp just fine. Unfortunately i do not have a scan tool.. On my to-get list(any recommendations on one would be great).

When i get home i want to feel the in and out lines to the core to see if they are hot.

Thanks

[college man]

[quote=”bwbell85″ post=122658]Hello college man,

Coolant is full, T-stat is only about 6-8 months old. Truck gets to temp just fine. Unfortunately i do not have a scan tool.. On my to-get list(any recommendations on one would be great).

When i get home i want to feel the in and out lines to the core to see if they are hot.

Thanks[/quote]

You can do the hose touching method. Unless you have an infrared thermometer
that would also help.check the lines in and out of the heater core. also
check the top radiator hose is hot. I know you dont have this but its a cool
video.

http://www.ericthecarguy.com/hvac/1106-solving-no-heat-problems

[Brad]

Dodge is notorious for heater core issues, I just had to back flush the heater core on my 2008 Avenger because of no heat…Had to replace the heater core in my 99′ Dodge Ram…I would at least do a feel test on the hoses…at temp with the heater running both hoses should be close to the same…

[Author]

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