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View Full Version : intermittent A/C when i accelerate ((weird))



vxodus
06/26/2013, 03:15 PM
here in the music capitol city, deep in the heart of texas, you'll see "keep austin weird" everywhere and the Vx fits in perfectly ~ but it's waaay to hot now for weird phenomena to be provoking my a/c ~ i've read quite a few threads but to no avail.
here's the deal ~ my 00-Vx a/c shuts off every-time i accelerate ~ when i let off the gas it comes back on, blows fine, cold & strong ~ when it shuts off (from accelerating) the a/c control panel lights & the battery light flickers ~ the rig runs fine while all this is happening ~ i've changed the a/c relay but the problem still exists ~ is this a load on the compressor issue?

FYI: before i bought this Vx a few months ago it supposedly had a noisy compressor-clutch issue that was "resolved/fixed", ...could this be a part of that repair?
prior to last week the a/c ran great ~ any ideas !!?

Marlin
06/26/2013, 04:40 PM
I believe there is a pressure switch in there somewhere, you accelerate, speed up the impeller in the pump, raises pressure, shuts compressor down. I am just speculating, but it sounds something along those lines, or it could be the other end, the alternator has issues, (think voltage regulator) and the AC isn't really turning off, just the electrical power goes away which shuts down the fan. It could be an electrical gremlin somewhere in the ac portion as well. Hook up a meter to your battery and then watch voltage while you rev the engine using the throttle assembly under the hood. May give you a clue, try that with the ac on and off and see if it changes anything.

vxodus
06/26/2013, 04:55 PM
:: yeah i'm hoping it's not a gremlin, catching them can get quite expensive ~ right now i have a "Live-Action/Turtle Man budget", so i'll try metering the battery to try and flush him out, ...with luck it's something minor.
the pressure switch is a good lead also ~ i appreciate the info Marlin ~ now i have some alternate directions to go after ~ i'll post the results ::

Y33TREKker
06/26/2013, 05:57 PM
Could this just be somewhat normal operating conditions for the VX? I know I've had vehicles in the past anyway that had simple A/C cut-out switches on the throttle linkage at the carb/throttle-body that would shut off the A/C under hard acceleration so that the A/C wasn't robbing the engine of power during acceleration. Those switches were usually set up to only activate near wide-open throttle conditions though, and I didn't see you mention how hard you'd been accelerating when you experienced the problem, but it's possible that newer vehicles incorporate something similar into the system using an input to the A/C controls from the throttle position sensor.

EVO
06/27/2013, 05:36 AM
Funny you should bring this up! I noticed this weekend while driving 85+mph withe A/C on in 90' weather that the fan does go into limp mode also! Had to set the vent to outside air to get the A/C cooling again while driving. Weird maybe the new normal for VX's!!

vxodus
06/27/2013, 09:21 AM
:: Hey Trekker, i wish it was something like a cut out switch, but i don't accelerate hard unless i need to (normal driving) ~ at any speed as soon as i push the gas pedal it cuts off ~ and to clarify, whether i'm going 10/mph or 70/mph and i let off the gas it comes roaring back on, but the whole while that pedal is depressed the lights flicker and the a/c is wavering (!?)

(!Ha) Evo ~ yea we don't need any more new-norms for the Vx ...unless it's something that makes it more awesome!

tom4bren
06/27/2013, 09:32 AM
lex,

Agree with Marlin. Check your altenator before you go digging into the AC system. Since your dash lights are flickering at the same time, it makes it sound more like a power supply issue rather than a problem with the AC.

Tom

vxodus
06/27/2013, 04:07 PM
:: yea i'm pretty sure that is the culprit ~ my Vx wouldn't start today at the shop and had that ol familiar dead battery clicking sound ~ no worries, i jumped it because the battery was below 13 at 10.7 ~ after jumping her back to life i did an alternator-check and it had very suspicious readings, so i opted to go exchange the battery first (core is probably dead anyway) and put the Vx into gear and my dash lights all started freaking out along with the tachometer!!!
after i replace the battery tmrrw i'll check the alternator again ~ if it's defective, which i believe it is, i'll get it rebuilt at a reputable local alternator shop ~ i really think this'll fix the weird phenomena.

QUESTION: i read somewhere on here that the Vx alternator is 90/watts but the alternator shop insisted that it was 75/watt, ...so what's the deal ?! anybody know ::

Marlin
06/27/2013, 05:14 PM
90 amps. I believe that is our rating, but 75 should be fine unless you are running major electrical extras. I know our little alternator is a mule, I run a 1000 watt amp, HIDs, and ton of electrical extras and I get absolutely not light pulsing, holds between 13-14 volts no matter what I throw at it, of course it is paired with an Optima, so that helps.

vxodus
06/27/2013, 09:09 PM
:: (oops) yess, amps ~ thx ~ glad to hear it's a mule.

is the alternator removal pretty straight forward? i haven't had a chance to check what i'm getting myself into yet ~ i've replaced the starter and that ma' ninja was a pain in the azz ~ i'll probably grab an optima battery while i'm at it ~ when i jump started the Vx the battery dipped down to 7 so it's pretty much dead.

any tips before i crack open the tool box and get on the creeper? ::