No heat, need help!
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Joined: Apr 2019
Posts: 89
Likes: 43
From: Johnstown, Pa
No heat, need help!
I'm the proud owner of a 90 vert 6 speed. I bought the car on ebay 2 years ago this month. I'm working through the minor issues the car has. I'm down to the bigger things. The heat blows cold. The electronic control unit appears to be working fine. I just replaced the blower control module and the fan now works properly. I checked both heater hose lines. They are both hot when the car is running so the heater core isn't blocked. I found the procedure to run diagnostic codes on the unit and I'm not getting anything. But I disconnected the battery for winter storage. But I assume that if there were any codes they would be stored. My best guess is that is the air blend door. I think It's set on cold. I believe the unit is mechanical. If it were broken I assume there won't be a code. Am I on the right path? If not any suggestions.
Instructor
Joined: Aug 2018
Posts: 168
Likes: 22
From: New York
Start the car, turn on the A/C and select the coldest inside the car temp you can. Turn the car off. Then remove the blower control module and using a flashlight look in the opening and you can see the blend door. Note the position of the blend door then reinstall the module. Start the car again, turn the A/C off and select heat increasing the temp inside the car to the warmest you can. Using the same procedure above you will be able to tell if the door is moving or not.
