WILL HEAT WORK WITH NO VACUUM

[Foxbodychris90]

I know it will be defaulted to the defroster vents but will the air coming out of the defrost vents get warm on a 1990 if there is no vacuum connected to the HVAC controls? if not what size hose connects to the rear of the HVAC controls to run out to the firewall?

thanks

 

[TOOLOW91]

As long as the blend door cable is hooked up it will get hot with the door on heat

Line is 1/8 inch I think

 

[Mustang5L5]

Blend door is cable actuated, so as long as you can move that and the door is functional, it will blow heat.

The line to the HVAC controls also contains a vac canister and check valve. Without these, when you go WOT and lose vacuum, the HVAC will default to defrost/floor and remain there until vac is restored

 

[Foxbodychris90]

As long as the blend door cable is hooked up it will get hot with the door on heat

Line is 1/8 inch I think

so long as i did not disconnect any cables in dash ill be safe with no vacuum from what i understand?

 

[Foxbodychris90]

Blend door is cable actuated, so as long as you can move that and the door is functional, it will blow heat.

The line to the HVAC controls also contains a vac canister and check valve. Without these, when you go WOT and lose vacuum, the HVAC will default to defrost/floor and remain there until vac is restored

what about at highway speeds not accelerating?
Blend door is cable actuated, so as long as you can move that and the door is functional, it will blow heat.

The line to the HVAC controls also contains a vac canister and check valve. Without these, when you go WOT and lose vacuum, the HVAC will default to defrost/floor and remain there until vac is restored