Ford F-150 Forum Discuss the Ford F-150 here.

New A/C stalls engine

Old 02-16-2013, 11:17 PM
Thread Starter
Join Date: Feb 2013
Location: Asheville, NC
Posts: 7
Default New A/C stalls engine

My 1992 F-150, 5.0, had to have a new A/C installed, when truck was "idling" and A/C came on it would stall the engine. The mechanic brought in the A/C distributor agent to help find the problem. No find on 1st unit. A second unit was installed and still could not find the cause why it was stalling the engine when A/C engaged. The electrical plug in to the unit receptacle had been previously damaged and a separate wire was installed in its place to the opposite end juncture of the connection. The mechanic was very positive this wire replacement was done correctly. To stop stalling the engine the RPM was increased from 500 to 750 which solved the engine stalling. I am still not happy with this situation. I bought the truck at 5 years old and the apparent original A/C never stall the engine and when it died it went out in smoke and froze and burnt up the serpentine belt.

Anyone experienced this? Any suggestions or solutions?

David S
Old 02-17-2013, 05:10 PM
RustyFordLover's Avatar
Senior Member
Join Date: Jul 2012
Location: Fairbanks Alaska
Posts: 492

What engine does the truck have? 500 sounds like rather a low idle RPM. Most Diesels idle higher then that. My truck idles at about 800. Have you tried revving the engine up, turning on the A/C, and then idling back down slowly to see at exactly what RPM it stalls out at?
Old 02-19-2013, 01:30 AM
Thread Starter
Join Date: Feb 2013
Location: Asheville, NC
Posts: 7
Default new a/c stalls engine

Thanks Rusty, it is not a diesel, its gas 5.0, 302/304 and EFI. I don't have a rpm gauge on the truck. My mechanic uses one of those expensive computer boxes to set rpm etc...
The 750 rpm is high enough to keep the engine from stalling. Supposedly the engine is idling at 500 rpm and when a/c comes on the rpm drops but engine does not stall and immediately and noticeably increases to the higher rpm. When a/c is turned off engine returns to the slower rpm.
Also the vehicle speed has to be higher than normal for the auto/mat transmission to shift gears when the a/c is engaged.
Both you and in2trux came on my email but I don't see his post here?

David S
Related Topics
Thread Starter
Last Post
Chevy Silverado/ GMC Sierra Forum
09-21-2010 06:10 PM
Chevy Silverado/ GMC Sierra Forum
11-23-2007 07:27 PM
Dodge Dakota Forum
07-27-2006 11:24 AM
General Motors Tech
05-21-2006 03:19 PM
Polaris 500
Chevy/GMC Small Trucks Forum
01-25-2006 01:48 AM

Thread Tools
Search this Thread
Quick Reply: New A/C stalls engine

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.