• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

1970 charger heater core question

davek

FBBO Gold Member
FBBO Gold Member
Local time
12:02 AM
Joined
Oct 14, 2017
Messages
13,763
Reaction score
21,816
Location
columbia SC
1970 charger with AC. Why are the core and evaporator so big? My 74 challenger had a small ones and it was an ac car. A non b body ac car has a small one .
1769899018365.png
 
Last edited:
I believe the reason for the dual heater core on the B & C body has to do with the A/C in the defrost mode. When in heat mode, both cores provide heat. When in Defrost mode there is a timer on the bottom of the heater box that runs the A/C compressor for a few minutes off and on. I think Mopar installed the H valve on the heater core to shut off half during defrost since that is the only time the H valve closes. Don't know if this explains it or the reasoning behind it but that is what makes sense to me. Here is a pic of the core with the H valve and a pic of the door to the A/C vents that gets closed whenever the defrost mode is running. I never had a A or E body with A/C so not sure if they have a timer

100_2385.JPG


100_2364.JPG
 
I believe the reason for the dual heater core on the B & C body has to do with the A/C in the defrost mode. When in heat mode, both cores provide heat. When in Defrost mode there is a timer on the bottom of the heater box that runs the A/C compressor for a few minutes off and on. I think Mopar installed the H valve on the heater core to shut off half during defrost since that is the only time the H valve closes. Don't know if this explains it or the reasoning behind it but that is what makes sense to me. Here is a pic of the core with the H valve and a pic of the door to the A/C vents that gets closed whenever the defrost mode is running. I never had a A or E body with A/C so not sure if they have a timer

View attachment 1987195

View attachment 1987196
My ‘69 Newport did that. Ran the AC for a little bit to get rid of inside fog. My two cars, both V code had none of that stuff.
 
Back
Top