A/C System Help!!!

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.

jfkelley

Full Access Member
Joined
Apr 14, 2019
Posts
65
Reaction score
15
Location
Oklahoma City
First Name
John
Truck Year
1976
Truck Model
K10
Engine Size
350
have an 1976 K10 Scottsdale 4X4, The A/C has been retrofitted it blows Semi Cold when Idling , But if I give it gas while sitting still the blower speeds up and blows cold, Also when you drive it you can hear it start blowing harder and its gets cold..A/C has been charged , All Ducts been inspected and are good..Do I need a new Clutch fan or Blower Motor ? Maybe one out of an 1994 Truck?..Plus the A/C Blows Max regardless what setting you have it on...Its HOT in Oklahoma Everyday way over in the 100’s today...Any Help or Advice would help ...Thanks !
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Sounds like you might have more of a voltage issue. If the blower speeds up when you rev the engine, your voltage may be dropping at idle. By retrofit, do you mean converted to R134A freon? That might be part of the problem too. From what I hear, the R134a requires a higher pressure and maybe the compessor isn't putting that higher pressure out at lower rpms.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
What rpm are you idling at? Auto or manual trans? Maybe bump the idle up a 100-200rpm for the summer. If you're at 500 rpm now, 700 won't be to bad.
 

Colin

Full Access Member
Joined
Mar 12, 2018
Posts
226
Reaction score
229
Location
Covington, GA
First Name
Colin
Truck Year
1978
Truck Model
K10 Silverado
Engine Size
350 cu. in.
Make sure the condensor isn't obstructed with dirt, etc. and is able to flow fresh air across the fins.
 

jfkelley

Full Access Member
Joined
Apr 14, 2019
Posts
65
Reaction score
15
Location
Oklahoma City
First Name
John
Truck Year
1976
Truck Model
K10
Engine Size
350
I have an 1976 K10 Scottsdale 4X4, The A/C has been retrofitted it blows Semi Cold when Idling , But if I give it gas while sitting still the blower speeds up and blows cold, Also when you drive it you can hear it start blowing harder and its gets colder..A/C has been charged , All Ducts been inspected and are good..Do I need a new Clutch fan or Blower Motor ? Maybe one out of an 1994 Truck?..Plus the A/C Blows Max regardless what setting you have it on low medium ..Its HOT in Oklahoma right now 118 today...Any Help or Advice would help ...Thanks !
 

dvdswan

Full Access Member
Joined
Mar 11, 2014
Posts
2,366
Reaction score
2,036
Location
Port Orchard, WA
First Name
Dave
Truck Year
1978
Truck Model
K10
Engine Size
350
To test your fan clutch, engine off, cold, and depending what the temp is outside (i.e. below 40* or above 100* the fan should turn with good resistance). Engine off and the engine is warmed up and 118* outside the fan should not turn at all.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Make sure the condensor isn't obstructed with dirt, etc. and is able to flow fresh air across the fins.
Yes, that too.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,134
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
Sounds like you might have more of a voltage issue. If the blower speeds up when you rev the engine, your voltage may be dropping at idle. By retrofit, do you mean converted to R134A freon? That might be part of the problem too. From what I hear, the R134a requires a higher pressure and maybe the compessor isn't putting that higher pressure out at lower rpms.

My thought substituted VACUUM for Hotrod's voltage issue. Increased engine speed reduces available inches of travel? Some ****. Is it blowing equally side to side or?

$525+or- to fix mine. That's the bar cuz I was seein about mine yesterday. :(
How much YOU got to spend? lol? Hot AF! :flamingdevil:
 

jfkelley

Full Access Member
Joined
Apr 14, 2019
Posts
65
Reaction score
15
Location
Oklahoma City
First Name
John
Truck Year
1976
Truck Model
K10
Engine Size
350
Thanks for all the replies ..No Baseball tourney this weekend , So I will try everyone suggestions & report back my findings
 

jfkelley

Full Access Member
Joined
Apr 14, 2019
Posts
65
Reaction score
15
Location
Oklahoma City
First Name
John
Truck Year
1976
Truck Model
K10
Engine Size
350
Sounds like you might have more of a voltage issue. If the blower speeds up when you rev the engine, your voltage may be dropping at idle. By retrofit, do you mean converted to R134A freon? That might be part of the problem too. From what I hear, the R134a requires a higher pressure and maybe the compessor isn't putting that higher pressure out at lower rpms.


Yes sir I was meaning R134A
 

jfkelley

Full Access Member
Joined
Apr 14, 2019
Posts
65
Reaction score
15
Location
Oklahoma City
First Name
John
Truck Year
1976
Truck Model
K10
Engine Size
350
I took a video of the AC Compressor with A/C going Belt flopping around

1st pic is at Idle with A/C on
2nd Pic is driving with A/C on

You must be registered for see images attach


You must be registered for see images attach
 

jfkelley

Full Access Member
Joined
Apr 14, 2019
Posts
65
Reaction score
15
Location
Oklahoma City
First Name
John
Truck Year
1976
Truck Model
K10
Engine Size
350
Please check your grounds as well including the battery posts. Bad ones can cause those symptoms
Please check your grounds as well including the battery posts. Bad ones can cause those symptoms


Check all the grounds I could find and cleaned them with wire brush and reinstalled and no change in AC ..Do I need a Bigger Alternator ?
 

Forum statistics

Threads
44,173
Posts
950,829
Members
36,287
Latest member
goodwrenchca
Top