1990 base coupe Heat just stopped!
02-19-2017, 12:10 PM
#1
Safety Car
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Member Since: Oct 2000
Location: Lake Wylie, South Carolina
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1990 base coupe Heat just stopped!
Everything was working fine but now the heater isn't blowing hot air only cool. The over flow tank is low but there are no leaks.
The low coolant may have come when I changed the injectors which requrited disconnecting the coolant line on the throttle body.
What all do I check??
Thanks!
The low coolant may have come when I changed the injectors which requrited disconnecting the coolant line on the throttle body.
What all do I check??
Thanks!
02-19-2017, 12:22 PM
#2
Melting Slicks
Assuming you have the C68(digital HVAC panel).
What temp does the digital display say for coolant? In case thermostat is stuck open?
It could be the blend door motor stuck to cool.
Could be a clogged heater core.
Could be the control panel is not commanding the temp to change.
Are the hoses to the heater core both hot with the engine warmed up?
Does the control panel seem to respond to commands as it should?
Where the air goes is vacuum, the temp is all electric.
If the hoses are both hot, set the temp to 90 and manually set fan to high. Vents to dash.
If it's still cold. I'd bet on blend motor. You can disconnect the evaporator casing and pull it back to see where the blend door is.
Here is a video on the diagnostics He is refering to section 1C1 in the FSM
What temp does the digital display say for coolant? In case thermostat is stuck open?
It could be the blend door motor stuck to cool.
Could be a clogged heater core.
Could be the control panel is not commanding the temp to change.
Are the hoses to the heater core both hot with the engine warmed up?
Does the control panel seem to respond to commands as it should?
Where the air goes is vacuum, the temp is all electric.
If the hoses are both hot, set the temp to 90 and manually set fan to high. Vents to dash.
If it's still cold. I'd bet on blend motor. You can disconnect the evaporator casing and pull it back to see where the blend door is.
Here is a video on the diagnostics He is refering to section 1C1 in the FSM
Last edited by belairbrian; 02-19-2017 at 12:32 PM. Reason: link added
02-20-2017, 04:59 AM
#4
Safety Car
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Member Since: Oct 2000
Location: Lake Wylie, South Carolina
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FIXED!
There is a small plastic vacuum line that has a rubber boot on the end. That boot connects to a vacuum port under the throttle body. The boot was still connected but the plastic line came out of the boot. Once I reconnected the line I started getting heat in the car again.
So I'm guessing that only the heater blend door is controlled by the vacuum from this port? All of the selector buttons were changing the air output location between defrost, dash, floor, etc. I was just not getting hot air.
I had a similar situation with the AC several months ago but that was the plastic vacuum line coming from a check valve near the driver side firewall.
DAMN THESE PLASTIC LINES!!! I wish they still used rubber lines like the older cars did. i never had to woory about rubber lines breaking in half or sliding out of connecting boots.
There is a small plastic vacuum line that has a rubber boot on the end. That boot connects to a vacuum port under the throttle body. The boot was still connected but the plastic line came out of the boot. Once I reconnected the line I started getting heat in the car again.
So I'm guessing that only the heater blend door is controlled by the vacuum from this port? All of the selector buttons were changing the air output location between defrost, dash, floor, etc. I was just not getting hot air.
I had a similar situation with the AC several months ago but that was the plastic vacuum line coming from a check valve near the driver side firewall.
DAMN THESE PLASTIC LINES!!! I wish they still used rubber lines like the older cars did. i never had to woory about rubber lines breaking in half or sliding out of connecting boots.