A/C Idle Up VSV works, when jumpered! Little help please...
03-13-2009, 09:00 PM
#1
Registered User
Thread Starter
Join Date: Apr 2008
Location: CenCal
Posts: 536
Likes: 0
Received 0 Likes
on
0 Posts
A/C Idle Up VSV works, when jumpered! Little help please...
Getting my A/C ready for summer, noticed I didn't idle up when I turned it on. Went under the hood, checked my connection at the VSV, was good. Checked the pigtail for power, got it on one of the two prongs, assumed the other was the ground. One thing I did notice was that I got power from the pigtail whether the A/C was on or not, kinda like it was triggered by the ignition, not the A/C. At this point I'm thinking it's a bad VSV, but I wanted to be sure. Ran a jumper ground and used my test light for the positive... IT WORKED! Heard a click from the VSV! Started the truck, jumpered it again. Idled up as it should! So.... with power at the pigtail and a working VSV, why am I not getting it to switch under normal operation? 
Thoughts? Ideas?
Thoughts? Ideas?
Last edited by qdude79; 03-13-2009 at 09:02 PM.
03-14-2009, 09:24 AM
#4
Registered User
Join Date: Mar 2006
Location: Beaumont, Tx
Posts: 1,028
Likes: 0
Received 0 Likes
on
0 Posts
I am going to keep an eye on this, because mine does the same thing, I havent tested it to see if it works when I jumper it, but I am curious...it gets annoying having to hold the gas pedal a little bit at stop lights, doesnt it!!!
Trending Topics
03-19-2009, 06:48 PM
#8
Registered User
My guess, and this is only a guess, is that there is a switch or relay on the ground side that when you engage your A/C is supposed to close and complete the grounding of the VSV up idle. Since I don't have my factory manuals handy, this is all just a big guess.
Did I mention that I'm guessing?
Did I mention that I'm guessing?
03-19-2009, 09:10 PM
#10
Registered User
Thread Starter
Join Date: Apr 2008
Location: CenCal
Posts: 536
Likes: 0
Received 0 Likes
on
0 Posts
Hey RobD... just read this in the FSM. What do you make of it?
"The current applied to the AC idle-up VSV flows through Terminal 9 of the (AC) Amplifier ->Ground, activating the VSV"
Can this info be good for anything?
"The current applied to the AC idle-up VSV flows through Terminal 9 of the (AC) Amplifier ->Ground, activating the VSV"
Can this info be good for anything?
03-22-2009, 07:15 PM
#11
Registered User
Thread Starter
Join Date: Apr 2008
Location: CenCal
Posts: 536
Likes: 0
Received 0 Likes
on
0 Posts
Ok, spent a bit of "quality time" with my test light and VSV today. At the connector in the pic, the connector is sideways.
The "bottom" of the two terminals is constant switched 12v, regardless of whether the AC is on/engaged or not. The "top" terminal (with the end of my test light stuck in it) is strange. No power shown, and when manually grounded (with my test light) will fire off the VSV and the idle will come up some. However, when the AC engages, the test light comes on dim and the VSV fails to function. I thought this was the opposite of what was supposed to happen!!
Some electric guru needs to help my ignorant ass! I'm beggin' ya!!
The "bottom" of the two terminals is constant switched 12v, regardless of whether the AC is on/engaged or not. The "top" terminal (with the end of my test light stuck in it) is strange. No power shown, and when manually grounded (with my test light) will fire off the VSV and the idle will come up some. However, when the AC engages, the test light comes on dim and the VSV fails to function. I thought this was the opposite of what was supposed to happen!!
Some electric guru needs to help my ignorant ass! I'm beggin' ya!!
03-22-2009, 07:23 PM
#12
Registered User
Join Date: Mar 2008
Location: Temecula Valley, CA
Posts: 12,723
Likes: 0
Received 4 Likes
on
4 Posts
Is the refrigerant charge good?
If the low pressure switch is off (meaning not enough refrigerant in the system), nothing other than the dash fan will work when you hit the a/c button.
If the low pressure switch is off (meaning not enough refrigerant in the system), nothing other than the dash fan will work when you hit the a/c button.
03-22-2009, 07:32 PM
#13
Registered User
Thread Starter
Join Date: Apr 2008
Location: CenCal
Posts: 536
Likes: 0
Received 0 Likes
on
0 Posts
AC works great. No issue there, aux fan kicks in, clutch engages, cold air, good reading from high and low off my bro's manifold. Just not enough rpm's at idle to keep it engaged when the clutch kicks in and drags down the motor about 150 rpms. VSV to the idle up valve doesn't function properly, though it will work when I jumper it manually.
03-22-2009, 07:46 PM
#15
Registered User
Thread Starter
Join Date: Apr 2008
Location: CenCal
Posts: 536
Likes: 0
Received 0 Likes
on
0 Posts
Agreed, but I'm not sure how. This thing was owned by a lady that barely knew where to put the gas nozzle in to, so I'm pretty sure under the hood was relatively unmolested. Don't see much opportunity to screw up wiriing. Then again, it is "electrical." Anything's possible...
03-22-2009, 07:49 PM
#16
Contributing Member
wiring get's brittle with age; I'm only assuming heat has gotten the best of it and cause with the 12v constant, or the switched ground to deteriorate... the fun part's going to be finding out where 
for some reason, I haven't had issues with mine now for a whole week... I think it finally fixeded itself
for some reason, I haven't had issues with mine now for a whole week... I think it finally fixeded itself
03-22-2009, 10:48 PM
#20
Registered User
This may help a bit.......
Check Fig. 2-12 under "mode sensors and switches"
http://autoshop101.com/
I'll dig for more, but you might want to also. Good site.
Check Fig. 2-12 under "mode sensors and switches"
http://autoshop101.com/
I'll dig for more, but you might want to also. Good site.
Last edited by thook; 03-22-2009 at 10:49 PM.
