1996 Dodge Ram fan works but no heat

MORT64

MEMBER
1996 DODGE RAM
5.9L
V8
2WD
AUTOMATIC
180,000 MILES

New pump new thermostat, flushed x2, New rad cap. Heat gauge gets and stays at norm running temp until I turn on heater fan then drops to approx 170 degrees and doesn't recover until I turn it off. Temp is Luke warm at that point. If it's a blend door accurate motor where is it? Is it difficult to fix?

4 Replies

HMAC300

MECHANIC
48,601 POSTS

This has a cable for a blend door operation, check to make sure it's not broken and that it moves door rod. However the door rod may be broken from the door and not opening. Also there are a couple of vacuum motors by gas pedal make sure there are no vacuum leaks.

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Tuesday, March 24th, 2015 AT 12:11 PM

MORT64

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3 POSTS

Thanks this is very helpful, I do know there aren't any vac leaks. This maybe a cheap fix other than my time thanks again !

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Tuesday, March 24th, 2015 AT 12:36 PM

MORT64

MEMBER
3 POSTS

But doesn't answer the question of why it drops to approx. 170 degrees when fan is turned on.

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Tuesday, March 24th, 2015 AT 2:51 PM

HMAC300

MECHANIC
48,601 POSTS

Because the blend door may be letting to much cold air in heater. Also check radiator for cold spots after warmed up. It should be the same all across if not the rad is not good.

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Tuesday, March 24th, 2015 AT 3:08 PM