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· Registered
169 Posts
Hi Guys,

I have a question here. Yesterday when its 20 degrees here my heater core decides to crap out on me:want: . im pretty sure its not plugged since i have 0 heat both sides. i found directions for replacement here thru searching, and found a new core for 48 bux in stock at pep boys. ima pick it up after work and replace the old one. in the instructions it says.

If you know it's the heater core, here's the instructions from my recently acquired 1996 service manual
Heater Core
Remove or Disconnect:
1)Negative Battery Cable
2)Partially drain coolant (how extacly do i do this?) (partially???):confused:
3)Glove box unit and right-side lower sound insulator
4) Programmer and electrical connectors. Refer to "Air Conditioning Programmer" in this section.(Can be seen below.)
5)Heater core cover.
6)Inlet and outlet heater hoses from heater core.
7)Two heater retaining screws.
8)Heater core.

Install or connect:
1) Heater core to heater case, securing with two screws.
2)Inlet and outlet heater hoses to heater core.
3) Heater core cover.
4)Programmer and electrical connections. Refer to "Air Conditioning Programmer" in this section.
5) Glove box unit and right-side lower sound insulator.
6)Negative battery cable.
7)Refill cooling system.(how extacly do i do this?) (partially???):confused:
Perform the "Air Mix Valve Adjustment" procedure found later in this section.

Air Conditioning Programmer
Remove or disconnect:
1) Negative battery cable
2) Right-side sound insulator and glove-box unit.
3) Vacuum and electrical connectors from programmer.
4) Programmer from vehicle.
Install or connect:
1) Programmer to vehicle.
2) Vacuum and electrical connectors to programmer.
3) Right-side sound insulator and glove box unit.
4) Negative battery cable.

Air Mix Valve Adjustment(Actually, the book calls this "Air Mix Valve Actuators" but I think it's what the service manual meant - Cadillac
mechanics, does that sounds right?)
Remove or disconnect:
1)Glove box
2)Unsnap rod from the plastic retainer on the actuator arm.
3) Two (2) screws from actuator.
4)Electrical connector.
6) Check air mix door for free travel.
Install or connect:
1) Actuator.
2) Electrical connector.
3) Two (2) screw to actuator.
4) Snap rod to plastic retainer on actuator arm.
5) Glove box.
IMPORTANT: After the actuator(s) has been replaced, the actuator(s) need to be recalibrated for proper travel. The ignition must be cycled ON
for 3 minutes to allow the programmer and the actuator(s) to recalibrate for proper travel.
up there in red how do i partially drain/refill the coolant? what the procedure? please respond i know you guys are excellent on this forum thats why i only come here for advice. TIA ALOT!:thumbsup:

· Registered
169 Posts
The blower was just replaced and it was blowing only cold air. so i drained the coolant reconnect that hose then popped out the sound insulator and the glovebox just to discover that the damn bland door got stuck...AARRGgghh. so i disabled the blend door from staying on the cold side and i now have heat and am takin back the heater core today. DOH!

· Registered
169 Posts
the actuator is bad. it was totally stuck. for a quick fix i took the arm off and luckily it was spring loaded to the heat side (yeessssss). NOW when it gets warm again i will have to replace the actuator right? is that fairly easy/cheap? just a ballpark.
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