• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Turning on AC/Idle issue


gw33gp

Well-Known Member
U.S. Military - Veteran
TRS Banner 2010-2011
Ham Radio Operator
Joined
Aug 7, 2007
Messages
1,728
Reaction score
531
Points
113
Location
Costa Mesa, CA
Vehicle Year
2002
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0 SOHC
Transmission
Manual
2WD / 4WD
4WD
Tire Size
33"
Recently, I have noticed that when I turn on my AC when idling, the idle will drop to around 500 rpm and the AC will kick out and the idle will go back up to normal. After a short time the AC will kick back in and go through the same cycle.

If I increase the rpm to a little over 1000 rpm the AC will kick in and stay on. If I then take my foot off the accelerator pedal the engine will almost die and the AC kicks out again. If I very slowly let up on the accelerator pedal the idle will take over at the normal rpm and AC works as it should. When I am driving stop and go the AC works as it should. It is just an issue when turning on the AC at idle.

I know the Idle Air Controller controls the idle and usually is quick to adjust the idle when the AC is turned on. It seems to be slow to respond now. I never had this problem before. Is it possible the IAC is sticking and could be the cause of this slow response? Is there something else that could cause this issue? I guess I could try cleaning the IAC to see if it helps.
 


fastpakr

Forum Staff Member
TRS Event Staff
TRS Forum Moderator
Supporting Member
Article Contributor
U.S. Military - Veteran
V8 Engine Swap
TRS 20th Anniversary
TRS Event Participant
Joined
Aug 6, 2007
Messages
7,991
Reaction score
2,794
Points
113
Location
Roanoke, VA
Vehicle Year
1999
Make / Model
Ford
Engine Type
V8
Engine Size
5.0
Transmission
Automatic
2WD / 4WD
4WD
Tire Size
285/75-16
That's definitely what I'd be checking/cleaning first. Also, is there anything in the documentation on how to test it electrically as well to ensure that the ECU is signaling to advance idle speed?
 
Last edited:

saara

Banned
--- Banned ---
Joined
Aug 11, 2017
Messages
1
Reaction score
0
Points
0
Vehicle Year
2017
Make / Model
carola
Transmission
Automatic
I still run my old Meyer 6 volt T-5 Snowplow pumps on 12 volts. The old 6 volt motors had really heavy windings. Today's motors, more than likely, have minimum gauge wiring and would fry.
 

85_Ranger4x4

Forum Staff Member
TRS Event Staff
TRS Forum Moderator
Article Contributor
V8 Engine Swap
OTOTM Winner
TRS Banner 2010-2011
TRS 20th Anniversary
VAGABOND
TRS Event Participant
Joined
Aug 7, 2007
Messages
32,213
Reaction score
17,528
Points
113
Location
SW Iowa
Vehicle Year
1985
Make / Model
Ford
Engine Type
V8
Engine Size
5.0
Transmission
Manual
I still run my old Meyer 6 volt T-5 Snowplow pumps on 12 volts. The old 6 volt motors had really heavy windings. Today's motors, more than likely, have minimum gauge wiring and would fry.
Be sure to check the windings in your IAC. :icon_rofl:
 

55trucker

Active Member
Joined
Aug 1, 2016
Messages
602
Reaction score
183
Points
43
Location
Oshawa, Ontario
Vehicle Year
1998
Make / Model
Ford
Engine Type
3.0 V6
Engine Size
3.0L
Transmission
Automatic
2WD / 4WD
2WD
Total Lift
-
Total Drop
mild
That's definitely what I'd be checking/cleaning first. Also, is there anything in the documentation on how to test it electrically as well to ensure that the ECU is signaling to advance idle speed?
Use a digital voltmeter & backprobe the contacts to the IAC, you should see the voltage on the meter change to correspond with the PCM commanding the A/C to engage & when the PCM disengages the A/C.
 

gw33gp

Well-Known Member
U.S. Military - Veteran
TRS Banner 2010-2011
Ham Radio Operator
Joined
Aug 7, 2007
Messages
1,728
Reaction score
531
Points
113
Location
Costa Mesa, CA
Vehicle Year
2002
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0 SOHC
Transmission
Manual
2WD / 4WD
4WD
Tire Size
33"
Please tell me what Meyer 6 volt T-5 Snowplow pumps have to do with an A/C and idle issues.


Thank you 55trucker for the advice on checking the IAC with a voltmeter. I will try that if cleaning the IAC doesn't work. I may have time this weekend to check things out.
 
Last edited:

55trucker

Active Member
Joined
Aug 1, 2016
Messages
602
Reaction score
183
Points
43
Location
Oshawa, Ontario
Vehicle Year
1998
Make / Model
Ford
Engine Type
3.0 V6
Engine Size
3.0L
Transmission
Automatic
2WD / 4WD
2WD
Total Lift
-
Total Drop
mild
Congratulations!:yahoo:

you've officially been spammed!
 

85_Ranger4x4

Forum Staff Member
TRS Event Staff
TRS Forum Moderator
Article Contributor
V8 Engine Swap
OTOTM Winner
TRS Banner 2010-2011
TRS 20th Anniversary
VAGABOND
TRS Event Participant
Joined
Aug 7, 2007
Messages
32,213
Reaction score
17,528
Points
113
Location
SW Iowa
Vehicle Year
1985
Make / Model
Ford
Engine Type
V8
Engine Size
5.0
Transmission
Manual
Congratulations!:yahoo:

you've officially been spammed!
I probably should have deleted it when I canned the poster, I thought it was funny and too off the wall to cause harm.

It is a repost of a post Doofy posted a few days ago.
 

gw33gp

Well-Known Member
U.S. Military - Veteran
TRS Banner 2010-2011
Ham Radio Operator
Joined
Aug 7, 2007
Messages
1,728
Reaction score
531
Points
113
Location
Costa Mesa, CA
Vehicle Year
2002
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0 SOHC
Transmission
Manual
2WD / 4WD
4WD
Tire Size
33"

Sponsored Ad


Sponsored Ad

Staff online

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top