Blower Motor Doesn't Move Much Air --- Normal?
#1436341
05/14/13 06:55 PM
05/14/13 06:55 PM
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Joined: Jul 2007
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North Carolina
cjskotni
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Guys, I have noticed that the blower motor in my Charger doesn't seem to move a lot of air. In fact, the motor on the 'high' setting moves about as much air as a modern car on the low-med setting. Is this normal? The blower motor is brand new but I noticed the motor itself if a bit shorter than the OEM. It seems all the aftermarket replacements are like this. I tested the motor before I put it in and it would about twist your hand of when you hit it with 12V so it felt pretty strong. When I got the motor, it just had two leads, one black and one orange which I tested in both polarities and it seemed the black to 12V and orange to ground moved air out of the vents. Dash ducts are totally clean and HVAC box is newly rebuilt and I have verfied that all the proper air doors are opening properly. Am I spoiled by the modern HVAC setups or did I mess something up here? Is this normal or maybe due to crappy aftermarket motor? Any thoughts are appreciated! 
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: 1_WILD_RT]
#1436346
05/14/13 11:17 PM
05/14/13 11:17 PM
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Joined: Jan 2003
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So Cal
Sinitro
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Heater blower resistor packs are readily available, $20-75 depending upon application.. No need to remove the heater box, EZ to change from the outside (2) screws and it just plugs in. Uses wirewound resistor coils that simply wear away due to heat and age, the resistors are in series for Low and Medium speeds to drop the voltage. And in High a full 12V is sent to the blower motor... Just my $0.02... 
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: 1_WILD_RT]
#1436347
05/15/13 08:15 AM
05/15/13 08:15 AM
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Joined: Jul 2007
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North Carolina
cjskotni
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Quote:
Quote:
Check the resister coils - that's usually the culprit as they just rust away - new and old cars alike! They're inside the heater box (subjected to all that nice moist air !!) right behind the power connector.
Quote:
too much voltage drop due to all the old wiring and switch contacts.
BS!
Since the high blower position bypasses the resistor bridge & since I've added relays to the blower on a dozen old Mopars & every one has made a huge difference I'm calling BS on you BS.... 
It's not the blower motor resistor. I re-did the HVAC box and they are tested, clean, and working in this case.
Th problem is still evident even on the high setting which bypasses the resistor pack entirely so that's not an issue.
I must have the damned thing wired backwards. 
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: cjskotni]
#1436348
05/15/13 09:56 AM
05/15/13 09:56 AM
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North Carolina
cjskotni
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Well I went ahead a reveresed the polarity of the fan via jumpers and it moves little to no air so I guess I did have it wired right... I am guessing this is normal then becuase the fan was getting near 14V at the connector @ high. I am a bit stumped at this point. That is why I was just wondering if this is normal for these older systems... 
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: cjskotni]
#1436349
05/15/13 11:01 AM
05/15/13 11:01 AM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
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Circle Track
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You certainly have plenty of voltage to it (14V) & everything is cleaned out/unobstructed & the blend doors are correctly positioned. If the motor is grounded well in effect to the batt neg post (check it) & nothing is mechanically slowing the fan blade inside of the housing it doesn't sound like anything else can be improved upon (unless we're still missing something). Maybe a new or different type of motor would spin faster
live every 24 hour block of time like it's your last day on earth
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: 3hundred]
#1436352
05/15/13 12:04 PM
05/15/13 12:04 PM
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North Carolina
cjskotni
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Quote:
Quote:
Dash ducts are totally clean
You're sure there's no leakage through the ducts or their joints?
Robert
The ducts are probably better than stock as I epoxied all the little gaps between the factory staples and sealed them up good when I had the dash apart.
I tested this before I had the ducts/dash in and it seemed the air coming from the big HVAC opening wasn't the greatest but I figured maybe the ducts would make it seem like more...I don't know..I'm not an HVAC guy. 
As far as the fan itself it really can go on one way. You have the clamp the holds it on the motor shaft and the only way to get at that is if you install it open side out (towards the evap). I don't see how I buggered that one up. As far as distance on the shaft, I am pretty sure it's not scrubbing the housing...is there something else I need to look for?
If I were to buy a new motor, where to get where you have bought a good one before? I think I got this one from RockAuto...
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: cjskotni]
#1436353
05/15/13 12:08 PM
05/15/13 12:08 PM
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Colleyville
3hundred
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Okay, I'm done. I'm virtually certain you should have just as powerful airflow as a new car. I don't recall ever being disappointed in the speed or volume of air flow in old cars when new.
Robert
'68 Fury Convertible
'69 300 Convertible
'15 Durango 5.7 Hemi
'16 300 S Hemi
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: 3hundred]
#1436354
05/16/13 02:57 AM
05/16/13 02:57 AM
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Chicago Burbs
sthemi
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The truth is, the older Mopar blower motors only put out a fraction of what GM cars did back in the day. they didnt work very well at all, as far as high volume airflow. your judgement of old Mopar high speed vs new anything low speed is dead accurate in my opinion, and I have had Mopars since '71.., before they were really old. The first Mopar I owned that actually was equal to the competition was a 78 Chrysler Newport with A/C. that car kicked out some air, both hot and cold. Also non air cars didnt have the same blower speed as A/C cars.
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: sthemi]
#1436355
05/16/13 10:51 AM
05/16/13 10:51 AM
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Lincoln Nebraska
RapidRobert
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Circle Track
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Lincoln Nebraska
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If everything is up to snuff & if it still ain't enough I wonder if a person could source a stronger/higher RPM motor that would fit in there.
live every 24 hour block of time like it's your last day on earth
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: 1_WILD_RT]
#1436356
05/16/13 11:00 AM
05/16/13 11:00 AM
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Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1
Too Many Posts
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Too Many Posts
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Posts: 28,312
Cincinnati, Ohio
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Quote:
Quote:
Check the resister coils - that's usually the culprit as they just rust away - new and old cars alike! They're inside the heater box (subjected to all that nice moist air !!) right behind the power connector.
Quote:
too much voltage drop due to all the old wiring and switch contacts.
BS!
Since the high blower position bypasses the resistor bridge & since I've added relays to the blower on a dozen old Mopars & every one has made a huge difference I'm calling BS on you BS....
I have to say that my 74 challenger with AC doesn't blow the same amount of air as my 99 chev pickup truck. But it blows plenty to keeps us cool on real hot days in a black car. I do notice my voltage goes pretty far down when it's on hi. After a little while I can put it on med and the black car will stay cool inside even on the hottest days. But I can hear the motor change when the electrical system is taxed and it effects my ignition I'm sure.
I'm wondering where you tap in Randy (if you don't mind me asking on this thread) to run my blower off a relay directly off the battery.
I am going to put my headlites on relays, actually I started last night, I think I understand how to do that and thought I would do my blower motor at the same time. TIA
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: Challenger 1]
#1436357
05/16/13 02:35 PM
05/16/13 02:35 PM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
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Quote:
Quote:
Quote:
Check the resister coils - that's usually the culprit as they just rust away - new and old cars alike! They're inside the heater box (subjected to all that nice moist air !!) right behind the power connector.
Quote:
too much voltage drop due to all the old wiring and switch contacts.
BS!
Since the high blower position bypasses the resistor bridge & since I've added relays to the blower on a dozen old Mopars & every one has made a huge difference I'm calling BS on you BS....
I have to say that my 74 challenger with AC doesn't blow the same amount of air as my 99 chev pickup truck. But it blows plenty to keeps us cool on real hot days in a black car. I do notice my voltage goes pretty far down when it's on hi. After a little while I can put it on med and the black car will stay cool inside even on the hottest days. But I can hear the motor change when the electrical system is taxed and it effects my ignition I'm sure.
I'm wondering where you tap in Randy (if you don't mind me asking on this thread) to run my blower off a relay directly off the battery.
I am going to put my headlites on relays, actually I started last night, I think I understand how to do that and thought I would do my blower motor at the same time. TIA
I would always take relays from the alternator stud. If you tap in from the battery side, it will have to pull all that current through the bulkhead connector (known weak point) and will also make your ammeter inaccurate. The same is true for any relays you will use (blower, headlight, fans, etc).
Relays are great for ensuring that the powered device (blower in this case) gets a good high voltage and plenty of current because the current path is much simpler as opposed to having to be pulled through the HVAC switch and bulkhead connectors which add resistance (and voltage drop). You will use the blower motor feed wire as the sensing wire for your relay.
This being said, if your charging system is losing the battle (discharging) when the blower is on, relays WON'T help....in fact they may make it worse. If you are seeing a large voltage drop meaning the alternator is not keeping up, this can only be fixed my increasing the power generation (hi amp alternator) or by reducing the loads (turn off accessories).
Also, as stated before, putting the blower on a relay will make it have one speed, HI because you are now bypassing the resistor pack.
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Re: Blower Motor Doesn't Move Much Air --- Normal?
[Re: sthemi]
#1436358
05/17/13 09:36 AM
05/17/13 09:36 AM
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Joined: Mar 2007
Posts: 9,336
South-Central (Sebring), FL
Commando1
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South-Central (Sebring), FL
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Quote:
The truth is, the older Mopar blower motors only put out a fraction of what GM cars did back in the day.
Pffffffftttttt..
Now here's where I have to call you out and say bull to that perception. The blower motor in old Mopars is a universal motor where in addition to Chrysler, was also used by GM. Check the interchange... 
The low air flow rate is not due to the motor. It was Mopar's sucky restricted heater box pathways.
Very poor design on their part.
The absolute best you can do is make sure you're getting full voltage when on 'hi' speed at the motor.
Since it is a brushed DC motor, you can increase the RPMs from it's stock rating by bringing it to a specialist and rewinding the motor.
But, who does that? Really! 
An easy but risky way to do increase RPM's is to use a 12V Step Up to 24V Voltage transformer Power Inverter. It may fry the motor.
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