Odd A/C vacuum issue.
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Joined: Feb 2017
Posts: 36
Likes: 4
From: Belen, NM
Odd A/C vacuum issue.
I've been having some vibration issues lately and I finally narrowed it down to a bad 2WD actuator (the ones up on the firewall by the battery).. I replaced that but now I'm having issues with the HVAC mode control.
A/C and heat both work fine in all positions (Max AC, AC, Panel, Off, Floor, etc....) at idle and under load, all the way up to full throttle - until I hit about 75MPH (speed limit here in NM is 75), and once I start hitting 80MPH and I go more than 1/4 throttle, the mode will switch from whatever I have it in (usually max AC) to Floor until I let off the throttle. I've checked all the engine side hard vacuum lines for broke lines, cracked lines, damaged boots, I've pulled the vacuum reservoir and verified that it's good (holds vacuum), checked the lines going from the actuators down to the front axle, and on and on.
I'm kind of running out of places to check or things to look at..... suggestions?
A/C and heat both work fine in all positions (Max AC, AC, Panel, Off, Floor, etc....) at idle and under load, all the way up to full throttle - until I hit about 75MPH (speed limit here in NM is 75), and once I start hitting 80MPH and I go more than 1/4 throttle, the mode will switch from whatever I have it in (usually max AC) to Floor until I let off the throttle. I've checked all the engine side hard vacuum lines for broke lines, cracked lines, damaged boots, I've pulled the vacuum reservoir and verified that it's good (holds vacuum), checked the lines going from the actuators down to the front axle, and on and on.
I'm kind of running out of places to check or things to look at..... suggestions?