Fummins ac compressor issues - PowerStrokeNation : Ford Powerstroke Diesel Forum
 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 04-13-2019, 03:34 AM Thread Starter
PSN Newb
 
rtracer39's Avatar
 
Join Date: Apr 2013
Posts: 17
Fummins ac compressor issues

Hi everyone, I'm looking for some help or insight from people out there that may have experienced this before. All my diagnostics keep pointing at the pcm.

My problem is when you turn the ac on in the cab the compressor isn't engaging. I started with all the simple things like fuses and relays. And checked to make sure I have the correct 1.1kg charge in it. I even printed the wiring schematics for the 6.0 engine harness and the entire ac system. I have power everywhere I'm supposed to according to the schematic but it seems as though the pcm output to the relay isn't working. I can even jump the relay with my power probe and it will engage the clutch. If I jump it at the high pressure switch it engages. I jump it on the pcm input at the high pressure switch it engages. I hook up our scanner at work and look at the pids for ac and its saying "ac not requested by driver" when the switch is on. So I'm kinda lost and getting frustrated.

A little about the truck.
April of 03 6.0 5r110 f450
Now using a 05 cummins and 13 68rfe auto
Ac wiring is 100% original ford minus the compressor pigtail
New compressor, condenser, accumulator, high pressure switch, clutch cycling switch and hoses all when the cummins was installed.
172k on the chassis. 117k on the motor. 1300 miles since the swap.
rtracer39 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 04-13-2019, 11:35 AM
Native Texan
 
masakimm's Avatar
 
Join Date: May 2016
Location: North Central Mo
Posts: 8,885
Garage
Re: Fummins ac compressor issues

Quote:
Originally Posted by rtracer39 View Post
Hi everyone, I'm looking for some help or insight from people out there that may have experienced this before. All my diagnostics keep pointing at the pcm.

My problem is when you turn the ac on in the cab the compressor isn't engaging. I started with all the simple things like fuses and relays. And checked to make sure I have the correct 1.1kg charge in it. I even printed the wiring schematics for the 6.0 engine harness and the entire ac system. I have power everywhere I'm supposed to according to the schematic but it seems as though the pcm output to the relay isn't working. I can even jump the relay with my power probe and it will engage the clutch. If I jump it at the high pressure switch it engages. I jump it on the pcm input at the high pressure switch it engages. I hook up our scanner at work and look at the pids for ac and its saying "ac not requested by driver" when the switch is on. So I'm kinda lost and getting frustrated.

A little about the truck.
April of 03 6.0 5r110 f450
Now using a 05 cummins and 13 68rfe auto
Ac wiring is 100% original ford minus the compressor pigtail
New compressor, condenser, accumulator, high pressure switch, clutch cycling switch and hoses all when the cummins was installed.
172k on the chassis. 117k on the motor. 1300 miles since the swap.
I have seen this before on these 6.0l. If you can jumper the switch then its a bad switch. the switches tell the pcm hey he wants ac and the system is good to provide it. If it was the pcm then jumping the switch would do nothing.Which switch are u jumping the duel pressure switch in the lines or the cycling switch on the accumulator. The cycling switch is a common failure. If u are jumping from one side to the other then bad switch if u are providing power to the wire. then check the violet wire from the control head. I had one go bad and ran a new one from the head to the cycling switch. Its not the pcm its not turning the ac on cause as far as it know its not wanted. because of a failure in the request line.

Give it to Mikey. He won't eat it he hates everything. Hey Mikey!! He Likes It.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Upgrades:
|Bellowed UpPipes|160CC Injectors|Adrenaline HPOP|Rebuilt Turbo 360 Bearing|Custom E-Fuel|Manual to Auto Conversion
|Delete Pedestal|3" Down Pipe 4" Exhaust|Dual Tensioner and Belt|Stainless Steel HPX Crossover|Custom Banks InterCooler
|42 Gal Rear Tank 35 Gal Front Tank |DP Infinity Tuner
masakimm is online now  
post #3 of 8 (permalink) Old 04-13-2019, 09:15 PM Thread Starter
PSN Newb
 
rtracer39's Avatar
 
Join Date: Apr 2013
Posts: 17
I can bypass the switch at the accumulator and it does nothing even though I have 12v on the violet. I move down to the dual pressure switch and I have 12v also. If I apply power to either tan and lt.green it will kick on the compressor. Both switches are new. I've evacuated and recharged the system 3 or 4 times now. I've put the 1.1kg in and it makes about 85psi on both gauges. I've tried to lower the charge down to about .5kg just to see if maybe it was overcharged. Still nothing. I even replaced the ac clutch relay to no end.
rtracer39 is offline  
 
post #4 of 8 (permalink) Old 04-13-2019, 10:00 PM
Native Texan
 
masakimm's Avatar
 
Join Date: May 2016
Location: North Central Mo
Posts: 8,885
Garage
Re: Fummins ac compressor issues

If u have 12v on the red/yellow wire u should have 12v on one of the tan/lt green wires. the blk/yellow should have ground and the other wire should be grounded. just cause u replaced the switch does not mean its good.

Give it to Mikey. He won't eat it he hates everything. Hey Mikey!! He Likes It.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Upgrades:
|Bellowed UpPipes|160CC Injectors|Adrenaline HPOP|Rebuilt Turbo 360 Bearing|Custom E-Fuel|Manual to Auto Conversion
|Delete Pedestal|3" Down Pipe 4" Exhaust|Dual Tensioner and Belt|Stainless Steel HPX Crossover|Custom Banks InterCooler
|42 Gal Rear Tank 35 Gal Front Tank |DP Infinity Tuner
masakimm is online now  
post #5 of 8 (permalink) Old 04-13-2019, 11:40 PM Thread Starter
PSN Newb
 
rtracer39's Avatar
 
Join Date: Apr 2013
Posts: 17
True about the new switch being possibly bad. That's the point behind bypassing it with a jumper wire. I haven't tried jumping both at the same time yet though.
rtracer39 is offline  
post #6 of 8 (permalink) Old 04-13-2019, 11:50 PM Thread Starter
PSN Newb
 
rtracer39's Avatar
 
Join Date: Apr 2013
Posts: 17
Since there are 2 tan/lt.green wires does it matter which is jumped to the red/yellow? I'll probably try that next. The more I think about it, the more it seems to be loosing the signal at the dual pressure switch.
rtracer39 is offline  
post #7 of 8 (permalink) Old 04-14-2019, 12:01 AM
Native Texan
 
masakimm's Avatar
 
Join Date: May 2016
Location: North Central Mo
Posts: 8,885
Garage
Re: Fummins ac compressor issues

Pin 1 is red\yellow
Pin 2 is Blk\yellow
Pin 3 is Tan\lt green for pin 2
Pin 4 is Tan\lt green for pin 1


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Upgrades:
|Bellowed UpPipes|160CC Injectors|Adrenaline HPOP|Rebuilt Turbo 360 Bearing|Custom E-Fuel|Manual to Auto Conversion
|Delete Pedestal|3" Down Pipe 4" Exhaust|Dual Tensioner and Belt|Stainless Steel HPX Crossover|Custom Banks InterCooler
|42 Gal Rear Tank 35 Gal Front Tank |DP Infinity Tuner
masakimm is online now  
post #8 of 8 (permalink) Old 04-14-2019, 01:09 AM Thread Starter
PSN Newb
 
rtracer39's Avatar
 
Join Date: Apr 2013
Posts: 17
Right. I was reading that when I got home a little while ago. My diagram says 1&4 go together and 2&3. So I'd need to jump red #1 to tan #4? Maybe I'll mess with it if it ever stops raining this weekend.
rtracer39 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the PowerStrokeNation : Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Fummins AC help splitshot Engine & Transmission Conversion 2 07-07-2013 08:21 PM
AC compressor wire question mrgto 7.3L Power Stroke Technical Info 2 03-22-2011 01:07 PM
Alternator/AC compressor bbbxcursion Engine & Transmission Conversion 5 10-28-2009 08:46 PM

Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome