I haven't posted in years,but having an issue. My blazer is factory ac,but i deleted it. I just want defrost for cold mornings for windshield. I dont have a vacuum line from engine to interior. I have the dash mostly apart and heater assembly removed. Do i need vacuum for just the defrost? The vacuum line scenario in my blazer is sketchy at best,lots of loose ends. I marked the ones that were still attached. I just want to be able to defog windshield if needed,im in norcal,and dont drive it much in the winter,or much at all really,lol.
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74 k5 ,just want defrost
- Thread starter BigBK5
- Start date
You might be able to build a set up using one of the small aftermarket heater cores and home built ducting. Mojave, JEGS has a unit, etc. Not sure how to control it unless a solenoid would work for you. My work truck uses a similar setup teed in to the heater lines to heat the bed unit. I can lift the hood and cut the ball valves off for the summer or leave them open to run the water heater coil.
Some of the hydronic/engine heater units people use in campers might be a source for controls or ducting ideas as well even if you aren't using a diesel heater.
Theres always the small electric units for occasional use as well. Not always super effective here with our humidity , ymmv.
Good Luck and let us know what you come up with.
Some of the hydronic/engine heater units people use in campers might be a source for controls or ducting ideas as well even if you aren't using a diesel heater.
Theres always the small electric units for occasional use as well. Not always super effective here with our humidity , ymmv.
Good Luck and let us know what you come up with.
https://www.jegs.com/p/JEGS/JEGS-Hot-Rod-Heaters/1697917/10002/-1
The 4th or fifth unit down offers a ducting kit as well.
The 4th or fifth unit down offers a ducting kit as well.
Got it working by lubing up and cleaning the blower motor,hooking back up the vacuum reservoir ball thingy to engine vacuum ,and connected to controller on dash. I blocked off the ac port on the box and defrost works great,i think. Hasnt been that cold here in norcal.
With no vacuum to the plenum, doors should default to defrost. You will have to have warm/hot engine coolant for it to work