TJ won't start while a/c is on - Jeep Garage - Jeep Forum

Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Wrangler-YJ, TJ & JK

Reply
 
Thread Tools Display Modes
 
  #1  
Old 06-15-2015, 01:15 PM
New Member
 
Join Date: Jun 2015
Location: Anderson SC
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
ohpoppy is on a distinguished road
TJ won't start while a/c is on

My 99 TJ won't start when A/C is in the on position. It will crank just won't start and run. Is there something in the PCM that links the a/c to the fuel pump or ignition. Nowhere online have I found any TJ's do this. Its not due to low battery or anthing.. it cranks fast.

Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 06-15-2015, 01:43 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: TJ won't start while a/c is on

Welcome to the garage.
So it does start when the AC is off? Does it continue running when you switch the AC on after starting?
As far as i know there is no connection between fuel pump nor ignition with regards to AC. The PCM will switch the AC compressor clutch and will increase a little bit the fuel injector pulse, just to compensate for the compressor drag.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #3  
Old 06-15-2015, 08:06 PM
New Member
 
Join Date: Jun 2015
Location: Anderson SC
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
ohpoppy is on a distinguished road
Re: TJ won't start while a/c is on

it starts and runs when ac is off
it continues to run when ac is switched on and get cold
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old 06-17-2015, 08:48 AM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: TJ won't start while a/c is on

For trouble shooting purposes i would disconnect the connector of the compressor clutch and see if it then starts.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #5  
Old 06-17-2015, 11:40 AM
New Member
 
Join Date: Jun 2015
Location: Anderson SC
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
ohpoppy is on a distinguished road
Re: TJ won't start while a/c is on

good idea.. if it starts the extra load of the compressor was the problem if not something in the pcm is the culprit .. is that your thought? I'll see.
Reply With Quote
  #6  
Old 06-17-2015, 10:03 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,616
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529939
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: TJ won't start while a/c is on

Quote:
Originally Posted by ohpoppy View Post
good idea.. if it starts the extra load of the compressor was the problem if not something in the pcm is the culprit .. is that your thought? I'll see.
Yes, thats it. But im almost sure that the PCM will not activate the compressor clutch before the engine is running, if it does, then that could be (part of) the problem. However i would not expect the compressor load to prevent it from starting, especially when it cranks with normal speed.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Jeep Liberty decides not to start every once in a while arcox Troubleshooting/Problems Discussion 8 11-30-2015 05:24 AM
2006 Grand Cherokee Overland won't start ! MrPostmanSAV Troubleshooting/Problems 24 11-29-2012 02:26 AM
2002 Overland Start-up Problem while Hot (Video) MikeBarillaro Troubleshooting/Problems 5 11-20-2012 07:32 PM
"Push to Start" message while parked overnight sdlimited Trouble Shooting/Problems/Service 9 05-06-2012 08:15 AM
Click Click Truck won't start cain45 Grand Cherokee - WK 24 10-06-2010 09:54 AM

» Premium Vendor Showcase
Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 09:22 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by FCA US LLC. Chrysler, Dodge, Jeep, Ram, Mopar and SRT are registered trademarks of FCA US LLC.