Topic: 2 questions as I change my heater core

[hankmeister]

Hey all, currently involved in one of our least fave activities.    Two questions:
1. Where the heck does the hotwire for the fan motor plug in?  It was just hanging loose in the engine bay, I believe it goes through one of the little holes in the firewall and plugs in....somewhere.
2. What the heck is this electrical thingy on the heater box? I can't even imagine what it could be for.

EDIT: 70 sportsroof with 351C, no air. Metuchen built.

Many thanks in advance!!
H

[hankmeister]

Here's the electrical thingy, coils inside the heater box, the prongs on the outside.

Thanks in advance

best
H

[ruppstang]

That is a resistor that gives you different fan speeds.

FYI it would help us to help you if you would tell us the year, model and assembly plant for your car.

[hankmeister]

That is a resistor that gives you different fan speeds.

FYI it would help us to help you if you would tell us the year, model and assembly plant for your car.

Interesting, and thank you.

Sorry, I thought my signature explained it - my fault, should've put that in the description. It's a 70 sportsroof with a 351C, built in Metuchen.

all the best
H

[ruppstang]

Sorry I missed it. Also some of us have more cars. LOL

[jwc66k]

Hank,
Get a set of Mustang Assembly Manuals and a Ford Shop manual for your year car. Most of what you need to know is in those documents.
Jim

[hankmeister]

Sorry I missed it. Also some of us have more cars. LOL

No worries! I should've put it in the title or opening sentence. 

Hank

[hankmeister]

Hank,
Get a set of Mustang Assembly Manuals and a Ford Shop manual for your year car. Most of what you need to know is in those documents.
Jim

Thanks Jim. I know from past experience that sometimes (often?) a wiring diagram doesn't show a realistic "location" for certain electrical components/connections. I searched around both under dash and engine bay, couldn't find an obvious connection for the blower motor. I'll get out the shop manual to see what I can find.

best
Hank

[hankmeister]

Well, just in case anybody has the same dilemma as myself in the future, it seems that from the wire coming off the blower motor and thru the firewall (seen in one of my photos above) there should be a short cable between that wire (with a female receptacle) and a squarish connector that attaches to the bottom prong of the resistor. While researching online I found and ordered a repair kit from NPD.com.

best
H

[hankmeister]

Well, just in case anybody has the same dilemma as myself in the future, it seems that from the wire coming off the blower motor and thru the firewall (seen in one of my photos above) there should be a short cable between that wire (with a female receptacle) and a squarish connector that attaches to the bottom prong of the resistor. While researching online I found and ordered a repair kit from NPD.com.

best
H

And lo and behold, I found the original short jumper wire tucked up against the firewall, behind the front(?) half of the heater box. Oh well.

It also seems my fan motor is not working...so I have the added pleasure of having to pull the heater core & box fully out, to install a new fan motor. Oh joy.

best
H

[DougDyar]

And lo and behold, I found the original short jumper wire tucked up against the firewall, behind the front(?) half of the heater box. Oh well.

It also seems my fan motor is not working...so I have the added pleasure of having to pull the heater core & box fully out, to install a new fan motor. Oh joy.

best
H

I have a NOS Motorcraft blower motor for sale if you need one. csx4068 at gmail dot com.
Doug

[hankmeister]

I have a NOS Motorcraft blower motor for sale if you need one. csx4068 at gmail dot com.
Doug

Thanks Doug. Did a direct jump from battery to blower, and even tho it whined a bit (as do most of us at 50), it still worked. So for now i'll save the expense. Next step is to swap out the fan switch on the dash control, and if that doesn't work then the resistor on the heater box, I reckon.

Again tho - thank you for the offer!

Hank

[hankmeister]

Old thread, but took the Mustang out today for a drive & wash. I drive the car every 3 to 5 weeks, about a 10 mile circuit (give or take) to keep it oiled up & running. As I was driving, I thought 'that smells like coolant'. Got to the car wash and saw coolant dripping from passenger side floorpan. So after only about 300-350 miles (and that's a generous guess, but I have to guess since the speedometer & odometer aren't functional) the heater core is once again leaking (badly) and has to be replaced. I've changed the coolant twice in the meantime too, so doesn't seem like that should be eating it up.  On the plus side, I never fully reinstalled the dash, due to other ongoing work.

best
Hank

[ruppstang]

I would check your grounds. Are you using a brass heater core?