Any explicit help on removing AC components and keeping heat?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

projo198

Junior Member
Joined
Jan 14, 2025
Posts
7
Reaction score
0
Location
Lawson MO
First Name
James
Truck Year
1978
Truck Model
K10
Engine Size
350
I've been trying to get a solid answer online and have had no luck.

My '78 K10 came to me with the outer heater box completely tore off. The only thing still there was the blower motor and housing.

I want to run heat only, no interest in restoring the AC (if it ever existed). The controls in the cab do show AC selections so I am guessing at one time it had it.

I have seen aftermarket "AC delete" boxes which appear to just connect the blower motor with the large square door in the firewall. I am in the process of fabbing my own to save money.

Is this job literally that simple? Does it require any modifications inside the cab?

Pic of my firewall. Any help/advice would be appreciated!

You must be registered for see images attach
 

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
2,504
Reaction score
3,931
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
That’s all that’s needed.

Technically, the air comes from the cowl area, goes down to the blower motor, the motor forces air thru the rectangular box, and then the various doors direct air thru the heater core, and to the various vents/outlets.

You will still need the vacuum line and vacuum storage ball to be able to control the function. Keep the heater control valve in the heater hose, whenever the temp is selected to full cold the water flow the heater core is blocked. Might keep things a little cooler in the cab.
 

projo198

Junior Member
Joined
Jan 14, 2025
Posts
7
Reaction score
0
Location
Lawson MO
First Name
James
Truck Year
1978
Truck Model
K10
Engine Size
350
That’s all that’s needed.

Technically, the air comes from the cowl area, goes down to the blower motor, the motor forces air thru the rectangular box, and then the various doors direct air thru the heater core, and to the various vents/outlets.

You will still need the vacuum line and vacuum storage ball to be able to control the function. Keep the heater control valve in the heater hose, whenever the temp is selected to full cold the water flow the heater core is blocked. Might keep things a little cooler in the cab.
Thanks much for the info!
 

Rustisbest

Super Access Member
Joined
Jul 20, 2021
Posts
242
Reaction score
686
Location
Athens, TN
First Name
Matt
Truck Year
1979
Truck Model
C10
Engine Size
377
You'll need a spot for the blower motor resistor too unless you just wire it on/off. Everything else can remain as is as already stated
You must be registered for see images attach
 

projo198

Junior Member
Joined
Jan 14, 2025
Posts
7
Reaction score
0
Location
Lawson MO
First Name
James
Truck Year
1978
Truck Model
K10
Engine Size
350
Well guys after debating cost and work involved I just ordered an under the dash auxiliary heater. Getting the right parts, even salvage, would have cost more.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,775
Reaction score
9,587
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Well guys after debating cost and work involved I just ordered an under the dash auxiliary heater. Getting the right parts, even salvage, would have cost more.
Pic and info on this underdash heater. Fwiw if your heater core is there,and your just trying to get some heat,don't care what things look like you can put a bilge blower under hood probably 10 bucks on amazon, wire it to run when the engines running or on a toggle,the under hood duct work would be simple with pcv and flex duct . Or just use @bucket leaf blower
 
Last edited:

Forum statistics

Threads
44,617
Posts
962,616
Members
37,158
Latest member
thom9719
Top