low heater output

Devon E

Devon E

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Joined
Jul 9, 2008
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299
K guys the heater in my truck blows hot air just not alot of it.
when the switch is on high it blows the same amount as it does on low.
The motor does not sound like it increases rpm as the switch is turned from low to high. also no sqeuling like i have had in the past with other blower motors going bad they all make horrible noises then die. I really dont wana rip the dash out to change the motor if there are other problems i can look at first Any common problems in this department Truck is a 99

Thanks for your help in advance guys
 
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The blower fan is an easy fix. Just four bolts and plug it in. Its up under where the passengers put their feet. No tearing apart of the dash needed.
 
It's not the fan, there is a resistor mounted inside the blower compartment, just trace the wires coming from the blower to find it. They are bad to kick the bucket due to the moisture inside the HVAC ducting. Plus it's about 1/3 the cost of the blower motor. If the motor is working, it's good, no change in speed it's the resistor.
 
I agree with Billysgoat....
Change the blower motor resistor and you should get all of your speeds back.
Its located on the bottom of the heater box,near the blower motor.Unplug it and remove the 2 phillips head screws and it should slide out.I did mine a few years ago as it was doing the same thing,resistor cost me about $70 from the dealer........Andy
 
Yea I missed the part where it doesnt change speeds. :doh: That is the resistor.
 
Hammer said:
I agree with Billysgoat....
Change the blower motor resistor and you should get all of your speeds back.
Its located on the bottom of the heater box,near the blower motor.Unplug it and remove the 2 phillips head screws and it should slide out.I did mine a few years ago as it was doing the same thing,resistor cost me about $70 from the dealer........Andy
Click to expand...

I think it was $30 or less from NAPA, when mine went kaput there was not a dealer close.

haloman said:
Yea I missed the part where it doesnt change speeds. :doh: That is the resistor.
Click to expand...

Reading comprehension is your friend! :poke:
 
Motor checked out ok the relay is changed but still just a trickle of heat from the vents with the motor running full speed. pluged heater core maybe ?

and i only get defrost ont the drivers side
 
Ayup, it be plugged. Drain the coolant, make an adapter to hook a water hose up to a heater hose and try to blow it out that way, if that doesn't work you can try compressed air. If that fails refill the system with plain water and about a quart or so of super clean, run it for the day like that and do a really good flush on the system.
 
Could be that your blend door is blocked and not allowing air out of that vent.
 
Thanks for the insight guys. im looking at pulling the heater core out now after finding some stuff that looks like a mouse or two made a home in there.

truck sat for about three years before i bought it
not guna complain to much tho got it for 4g and a VP and this are the only things wrong with it
 
Problem fixed remove blower fan reach up and vacum the completly packed solid heater core
Once the mouse nest and tons of dirt was removed heater blows lots of air
also changed the thermostat after witch was broken right off and the truck warms up and hold operating temp nice now.

Thanks for the help guys
 
Speaking on this subject.The resistor under the dash will need to be replaced if heater will not hit high.If you dont have cridders:poke: The resistor failing can be because the fan motor is bad.So before you get a resistor check the motor. Ask me how i know.Yes ,i am so smart i get to pay twice!
 
reviving this subject with a different problem... My truck will blow a lot of air but no heat... I took the glove box out and felt the water lines coming out of the heater core and nearly burned my finger on both of the lines...that tells me water is circulating through the heater core.

I don't know how to check to see if something is broke on the blend door, as the motor moves smoothly as you change the temperature knob?

Is it possible to remove the bottom half of the heater box without removing the dash? What else is there to check?

Lavon
 
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