No heat from heater 1990 ZR1

[Mystic ZR-1]

Yep, I see the glove compartment lid doesn't
fit well on your car either...
Typical GM quality.
Never seen one that's right.

[-=Jeff=-]

Originally Posted by Mystic ZR-1

Yep, I see the glove compartment lid doesn't
fit well on your car either...
Typical GM quality.
Never seen one that's right.

picture is not my car, but mine is the same way

[jrd1990zr1]

Originally Posted by Mystic ZR-1

Yep, I see the glove compartment lid doesn't
fit well on your car either...
Typical GM quality.
Never seen one that's right.

So Doug have you ever pulled the glove box to get the the heater box?? Before I start ripping and tearing thought I would ask. How was Carlisle, wish I had gone.

John

[-=Jeff=-]

glove box is 9 screws I think.. Pretty simple

[QB93Z]

Originally Posted by jrd1990zr1

Jim,

I see no movement of a door through the heater resistor hole. Top line to heater core is about the same as the metal crossover, however the return(lower) metal line from the heater core is significantly cooler.

I don't see anything in the 1990 FSM about getting to the door, door actuator or motor. Have you done this on your car? Am I missing something in the FSM?

Thanks again, John

No Movement of the Blend Door is a good indicator of a problem. I did a repair (replace) to my Blend Door Motor on a 1994 ZR-1 which does not have a glove box and the blend door motor is on the bottom of the AC Duct.

The operation and diagnosis of the HVAC controls is (in the 1994 FSM) described in bits and pieces in Volume 1 and in Volume 2 and it takes a fair amount of research to figure it all out.

Here is the Thread where I fixed my problem which may be similar to yours>

http://www.zr1.net/forum/showthread.php?t=27542

Jim

[BigJohn]

Originally Posted by -=Jeff=-

BigJohn..

here is a picture to help you

Cool Beans!
I have storage in both doors so the passenger could have their own gloves storage!
There is also a box behind the passenger seat!

[-=Jeff=-]

As years progressed we got less space

First years (PRE-ABS) 2 full depth storage bins behind seats
my 90 is full depth right and little tray on left

I also have 94 panels so I have the glove bx AND the door storage

[QB93Z]

John,


The Blend Door is controlled by a small electric motor and uses an electronic circuit to send position feed back to the AC Programmer. When the car is first turned ON, the AC Programmer sends a sequential full heat and full cool command to the Blend Door Motor. Since you are not seeing the movement, either the motor has failed, the AC Programmer has failed, there is a wiring problem, or the door is stuck.


I haven't investigated the access to the motor on a 1990 yet, but when you get to it, you can remove it and observe it's operation not connected to the door. And you can try to move the door by turning the pivot rod.


I have a complete set of the duct work from a 1991. I did not see it in the car so I don't know exactly how much you have to take apart to get to the motor.


If you need trouble shooting help when you get to the motor, call me. I will be glad to help.


Jim
443-244-1347

[jrd1990zr1]

Originally Posted by QB93Z

John,


The Blend Door is controlled by a small electric motor and uses an electronic circuit to send position feed back to the AC Programmer. When the car is first turned ON, the AC Programmer sends a sequential full heat and full cool command to the Blend Door Motor. Since you are not seeing the movement, either the motor has failed, the AC Programmer has failed, there is a wiring problem, or the door is stuck.


I haven't investigated the access to the motor on a 1990 yet, but when you get to it, you can remove it and observe it's operation not connected to the door. And you can try to move the door by turning the pivot rod.


I have a complete set of the duct work from a 1991. I did not see it in the car so I don't know exactly how much you have to take apart to get to the motor.


If you need trouble shooting help when you get to the motor, call me. I will be glad to help.


Jim
443-244-1347

Thanks Jim.
As always you're a life saver. Seems like this could be a big job and I hate to pull the car apart until the weather turns cold. I am going to pull the hush panel and glovebox over the weekend and see what I find. I've never been under that side of the dash. Thanks again, I'll let you know what I find.

Best, John

[-=Jeff=-]

John,

Keep in mind the carpet part on the Pass side is part of the WHOLE Dash pad, there is the lower hush but it allows a limited view