Heater Blower Motor

s10blazerman4x4 · #1 01-29-2005, 06:50 AM

My dad has a 91 4.0 and he only has a little heat when it is on high. We took the wiring bracket out to the motor cleaned the inside of both the wires and connector and it worked for a day really good. It went again yesterday morning he told me. Is this a sign of a dead blower motor or resistor on its way out? Any help would be good.

B33p3r · #2 01-29-2005, 08:53 PM

You say it only has a little heat when it is on high? Gotta do a little better. The blower motor is only responsible for blowing air. When on high, do you have a strong air flow from the vents? If so, the blower motor is doing its job. The heat part of it comes from the "Blend Door". It's job is to mix hot and cold air depending on your heat setting. Which is it? maybe we can help more.

s10blazerman4x4 · #3 01-29-2005, 09:11 PM

no heat at all but when onhigh u get air flow no heat then when we played w them wires we got heat but none now

molehole · #4 01-30-2005, 06:49 AM

So you get airflow but no heat? Sounds like a few scenarios-
1. Possibly a mulfunctuning thermostat

2. Maybe the blend door is not working properly
see this link: http://www.blenddoorfix.netfirms.com/

3. If you don't get enough airflow the blower motor is probably getting ready to take a dirt nap.

There is a resistor somewhere but I am not sure. That could also be part of the problem.
Check this stuff first
Good Luck

s10blazerman4x4 · #5 01-30-2005, 08:57 AM

will do and will ask him later thanks so far for the help

s10blazerman4x4 · #6 01-30-2005, 07:43 PM

you get on high little airflow with some heat but you can not hear the blower motor like you used to do when it was on high if it is on low no air flow or heat and if its on medium no heat no air flow

molehole · #7 01-31-2005, 03:32 PM

If it isn't the blower motor, there could be a blockage somewhere. Sounds like th eair can't get into the cab.

s10blazerman4x4 · #8 01-31-2005, 07:32 PM

no the air is ice cold so i think it probally is motor

molehole · #9 01-31-2005, 08:40 PM

Well if the air that it DOES put out is ice cold I would seriously see if it has a bad thermostat. What are the temp guages doing. I had problems with my 94 when the relay under the hood was malfunctioning and it would just cut out. It ends up that the relay just needed a tap and it was fine. The next step is to see if there is a blockage somewhere or if the controls themselves are not working properly. If it were the blower motor you would still get a little warm air with whatever air flow comes out of it. The fact that it is cold makes me think that something else may be wrong also. i know the later model Explorers have a lot of problems with the blend door which controls the air flow and the temperature of it. I am not sure what the set up is in the 91 but I know the 95-present have the set up in the link I posted above. Good Luck

B33p3r · #10 01-31-2005, 09:19 PM

Either Molehole is right about a blockage or you have 2 problems. Possibly a bad heater core? Smell any antifreeze in cab or oil residue on windshield? If core collapsed ...that could be your blockage Molehole is suspecting. Never eliminate the possibility of Mice building a nice warm house for the winter in your ductwork. (they only need the slightest opening) Pull the blower and check your ductwork.

s10blazerman4x4 · #11 02-01-2005, 05:59 AM

there is no antifreeze in the car or smell of that that i would know because i had the core go out on my blazer and u get a nice mess and we checked the ducting already because thats what i thought originally something could have gotten in there. it could be a block but you dont hear the heater blower at high like you used to

Phoenix69 · #12 02-01-2005, 04:49 PM

Possibly a clogged heater core? Maybe the car needs its coolant flushed, i have this problem in my grand prix, read into it and that may be the case.

s10blazerman4x4 · #13 02-01-2005, 06:54 PM

Well were gonna do the motor over the weekend and probally flush the system anyway> The Cav we just bought for my mom has no heat but that i think is the clogged core seeing how the thermostat has been changed.

s10blazerman4x4 · #14 02-03-2005, 04:59 PM

ok we fixed the problem tonight it was the motor it was all siezed up inside and then we dropped it on the ground and it freed up but we put the new one on and attached the old wheel. thanks everyone here was a big help

molehole · #15 02-03-2005, 05:54 PM

THats good. Good Luck with it.

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