Actually...the HEAT lever opens the door between the VENT and the Heater Core.  The stock heater has a Cabin Door which can be opened manually to allow fresh air in from the right cowl vent.  By closing that Cabin Door and moving the HEAT lever to Heat, air is directed through the heater core according to the position of the TEMP lever.

BB1.

I switched over to a Dakota Digital gauge system.  It gives a temp warning at 220 degrees.  

This is precisely why I'm upgrading to the 24 inch radiator w/ dual fans.  I suspect that will fix the problem regardless.

HEAT goes to passenger side of heater assembly.

TEMP goes to center top on heater box.

DEF goes to transmission tunnel by gas pedal.


As for air flow goes...if HEAT is on full vent barely any air comes out.
I would check cables are working as described in picture first.
I think you may have had full vent and no air was going thru heater box at all.

When you do get air flow...try reversing the 2 connectors to fan in engine compartment to see if airflow increases or decreases. I have connected those backwards in the past too...especially after motor replacement.

I am running a stock size aluminum radiator (2 row, 1” tubes) for a 289 no a/c and no problems.
I’m running an electric fan as well.

Last edited by Nos681 (11/30/2020 6:35 PM)

Just re-read your initial post.  You say the heater makes warm air but not much wind.  If your system is pulling down the voltage that could possibly cause the instrument system to indicate erroneously.

 

Nos681 wrote:

HEAT goes to passenger side of heater assembly.

TEMP goes to center top on heater box.

DEF goes to transmission tunnel by gas pedal.


As for air flow goes...if HEAT is on full vent barely any air comes out.
I would check cables are working as described in picture first.
I think you may have had full vent and no air was going thru heater box at all.

When you do get air flow...try reversing the 2 connectors to fan in engine compartment to see if airflow increases or decreases. I have connected those backwards in the past too...especially after motor replacement.

I am running a stock size aluminum radiator (2 row, 1” tubes) for a 289 no a/c and no problems.
I’m running an electric fan as well.

 I agree - low airflow after doing a heater rebuild is most likely the wires swapped. Polarity makes a big difference on fan operation. I did the same and got the wires reversed. Very low airflow - swapped wires back, and much higher airflow.
 

TremendousWand wrote:

Temperature is the temperature.  No fancy science or technology about it.  I'm running the 1966 16 inch radiator all be it an aluminum one.  (I purchased the car w/ this radiator.)  It's supposed to be able to cool up to 300 hp which it does (sort of). The car holds temperature but when idling too much it starts to creep up.  W/o the electric fan it would over heat really quick.  The stock foxbody radiator was 24 x 18 w/ a fan and shroud.  So I'm definitely undersized regardless.

I often wonder what people do to their cars to cause overheating. Most forums on this topic seem to involve electric fans and aluminum radiators. I know of people that remove the electric fans and aluminum radiator and go back to the original set up.
As you say, temperature is temperature and there is no fancy science, but do the electric fans complicate a simple system that Ford designed and worked well?

Toploader wrote:

TremendousWand wrote:

Temperature is the temperature.  No fancy science or technology about it.  I'm running the 1966 16 inch radiator all be it an aluminum one.  (I purchased the car w/ this radiator.)  It's supposed to be able to cool up to 300 hp which it does (sort of). The car holds temperature but when idling too much it starts to creep up.  W/o the electric fan it would over heat really quick.  The stock foxbody radiator was 24 x 18 w/ a fan and shroud.  So I'm definitely undersized regardless.

I often wonder what people do to their cars to cause overheating. Most forums on this topic seem to involve electric fans and aluminum radiators. I know of people that remove the electric fans and aluminum radiator and go back to the original set up.
As you say, temperature is temperature and there is no fancy science, but do the electric fans complicate a simple system that Ford designed and worked well?

Unless the fans some how violate the thermodynamic laws of the known universe and somehow add heat to the car then the fans have nothing to do with it.  Car has been holding temperature fine.  Radiator and electric fan is the same setup on countless millions of car new and old.  

It's all a moot point.  Like I said, I need a proper radiator regardless.  Just weird that the temperature went up w/ the heater on.  

Just closing this up, whoever said it first was right: wires were switched on the blower motor.  Very odd... blower motor has one red and one black wire and the wiring harness has one red and one black wire and I thought red-red, black-black because why the hell not?  For whatever reason it's red-black, black-red on my ride.

Car is holding temp just fine working as supposed to.  Temp stays between 180-195 (I have a 180 thermostat) and fan kicks on and off at just like it's supposed to.  On a side note: I was pleasantly suprised at just how nice and toasty the warm air was coming from the heater box.  With such a small cabin, doesn't take much to warm up.  Still not driving it in anywhere close to freezing temps with the summer tires but we stay in the mid 50s in most afternoons around these parts in the winter.  That's solid driving temperature for an afternoon out.

Toploader wrote:

I often wonder what people do to their cars to cause overheating. Most forums on this topic seem to involve electric fans and aluminum radiators. I know of people that remove the electric fans and aluminum radiator and go back to the original set up.
As you say, temperature is temperature and there is no fancy science, but do the electric fans complicate a simple system that Ford designed and worked well?

 
This is how i look at what has worked for me.
I personally gave up on temp switches for fans, even using relays.

The old mechanical fans didn’t have a clutch.
Therefore, the thermostat regulates temp in the engine by opening and closing as needed.

By operating the electric fan continuously, the thermostat performs the same exact operation.

Problem I read the most about is when air conditioning is involved.

For those who remember driving in the 1970-1980’s, I was too young to drive, there used to be signs along long uphill grades that advised drivers to turn off their air conditioning.
I remember asking my dad about it and why.
With his past experience as a semi truck driver, he explained the affects of the condenser contributing to cooling problems...never forgot it.
It happens on the Grapevine in California all of the time...even in newer cars.

TL...I learned a lot about the affects of timing and vacuum advance.
Self inflicted problems due to lack of knowledge and experience.