Dash heater controls vacuum pump

Furnace, air conditioning, thermostats, distribution.
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Posts: 96
Joined: Sun Oct 27, 2019 7:26 pm
Location: Spokane, Washington

Dash heater controls vacuum pump

Post by 05wingrider »

Two years ago the vacuum pump for my dash controls ran what seemed like all the time, so we pulled everything apart and found a few of the vacuum lines were loose and fixed them. Seemed to fix it, so pressed forward. This year same thing - you change the selector valve, and nothing really changed in the airflow, and even with the fan on high the airflow to the dash was miserable. It dawned on me that the vacuum pump that operates all the blend doors was the original one, and since my rig is a 96, who knows how old the actual pump is! I went on Ebay (Amazon has some of the same exact ones) and did a search for 12VDC Mini Vacuum Pump and just replaced mine.

The difference was shocking to say the least - the new pump ran for maybe 2 seconds and then shut off, but the biggest change was that prior to this if I wanted to change from - say dash vents to floor vents, I had to turn my fan down because it would take several minutes for the blend doors to move with too much air pushing against them. Now? I can have the fan on high and change the position valve, and it changes just that quick. I have mine set for recirculation most of the time, which puts the airflow to my dash vents - and I've got more airflow now than I've ever had to my dash vents.

The one I got is a Feiyinsi model ZX512-9006-4800 - (Manufactured in 2016) -90kpa Mini Membrane Vacuum Pump (13 psi), but I imagine ANY of the small 12 volt vacuum pumps would be an improvement if you're having issues like I was with the dash selector controls on your rig.
96 Sahara 30', 250hp Cat 3126
Allison 6spd MD-3060
2015 Jeep Cherokee Trailhawk "Toad"
Spokane WA
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