A/C clutch not engaging???

bossier62guy · April 20, 2013

You are correct. I added 34" core for more cooling power and my bully dog tuner has my tranny temp. gauge

Cool....now humor me a little....disconnect that manual switch from the VSC and see what you have. Just the one wire that runs to the controller....and which terminal is it connected to?

LongrangeLauber · April 20, 2013

I dont have the manual turn on hooked up to the VSC because it would not work for me. There are actually three wires that run to the fans that are needed to work. The two temp. probe wires as well as the turn on lead. Not entirely sure what you want me to do...

bossier62guy · April 20, 2013

I dont have the manual turn on hooked up to the VSC because it would not work for me. There are actually three wires that run to the fans that are needed to work. The two temp. probe wires as well as the turn on lead. Not entirely sure what you want me to do...

Actually a picture of the VSC would be nice....did you disconnect the A/C compressor clutch wire?

LongrangeLauber · April 20, 2013

I have kept it unhooked (just as I have with the manual turn on lead) ever since I installed the fans, because it kept them running. Give me a second, and I will go take a pic right quick

There ya go bossier62guy... FYI the green wire hanging at the bottom is the a/c turn on wire

bossier62guy · April 20, 2013

Ok....so w/ the A/C compressor signal wire off do the fans work correctly? Have you checked the LED's on the VSC per the instructions to make sure you're getting the correct lights?

bossier62guy · April 20, 2013

Do you have a multimeter? If so did you check the A/C wire to make sure it's not hot all the time? You could use a test light as well.

LongrangeLauber · April 21, 2013

Ok....so w/ the A/C compressor signal wire off do the fans work correctly? Have you checked the LED's on the VSC per the instructions to make sure you're getting the correct lights?

Yes, fans work flawlessly with a/c signal wire disconnected. The LED's are correct on the vsc when the fans kick on at the set temp.

bossier62guy · April 21, 2013

Yes, fans work flawlessly with a/c signal wire disconnected. The LED's are correct on the vsc when the fans kick on at the set temp.

Great....tells me the controller is working properly then. You have to have some power on that green wire. You do have it piggy backed on the 2 wire clutch connector (green wire) correct? What terminal on the VSC did you have it connected to? Do you have a way to check for voltage on that wire? I know you had/have some A/C issues as well. You need check the green wire at the VSC to see if it's hot all the time. If it is go to the plug on the compressor clutch and see if it's hot all the time. Let me know.

LongrangeLauber · April 21, 2013

Great....tells me the controller is working properly then. You have to have some power on that green wire. You do have it piggy backed on the 2 wire clutch connector (green wire) correct? What terminal on the VSC did you have it connected to? Do you have a way to check for voltage on that wire? I know you had/have some A/C issues as well. You need check the green wire at the VSC to see if it's hot all the time. If it is go to the plug on the compressor clutch and see if it's hot all the time. Let me know.

I do have it piggybacked on the green wire going to the clutch. I will pull out my test light and check it when I make it outside. I wonder if it makes a difference which harness plugs into the a/c accumulator cause I have two connectors coming off the wire loom and I just kind of picked one and plugged it in

bossier62guy · April 21, 2013

Check the plug when you can and we'll go from there. Also let me know what color the wire(s) are on the accumulator switch and I'll check the schematics. Although it shouldn't be hot if the HVAC control is turned off.

bossier62guy · April 21, 2013

One connector is gray, the other is white....the white one should be connected to the accumulator.

LongrangeLauber · April 21, 2013

One connector is gray, the other is white....the white one should be connected to the accumulator.

2013-04-21 11.42.11 (640x480).jpg

I jumped the low pressure switch (pictured) with a paper clip and then hooked up my turn on lead to the VSC. Turned the truck on and hit the A/C button and there ya have it, it kicked on, and when I turned the A/C off, so did the fans. The reason they didnt come on and off (Im guessing) is because the low pressure switch told the clutch not to engage if Im not mistaken. Thanks bossier62guy for all the help in troubleshooting the fan delima and to everyone else with the a/c clutch issue

bossier62guy · April 21, 2013

I jumped the low pressure switch (pictured) with a paper clip and then hooked up my turn on lead to the VSC. Turned the truck on and hit the A/C button and there ya have it, it kicked on, and when I turned the A/C off, so did the fans. The reason they didnt come on and off (Im guessing) is because the low pressure switch told the clutch not to engage if Im not mistaken. Thanks bossier62guy for all the help in troubleshooting the fan delima and to everyone else with the a/c clutch issue

I'm glad it's working but your theory is wrong LOL....just some gee whiz info for you.

If the PCM doesn't get a ground signal from the low pressure switch then it does not provide a ground to the A/C compressor clutch relay and therefore you don't get the 12V to the compressor clutch. The FAL controller only needs 12V on terminal 8 to tell it to kick the fans on. If it gets nothing there then you should have no fan activation. Regardless, it's nice that part of your problem is over. You didn't say whether or not you had the correct plug on the low pressure switch.

LongrangeLauber · April 21, 2013

I did have the correct plug on the low pressure switch (white one)... not sure why it all of a sudden worked, because before, I would keep that turn on lead hooked up and it would run the fans until the battery died. Maybe now that it can ground the signal it shuts the fans off as well? I probably just reworded exactly what you just said

bossier62guy · April 22, 2013

I did have the correct plug on the low pressure switch (white one)... not sure why it all of a sudden worked, because before, I would keep that turn on lead hooked up and it would run the fans until the battery died. Maybe now that it can ground the signal it shuts the fans off as well? I probably just reworded exactly what you just said

Beats me but it's nice it's behaving like it should.....if you have any more problems with it just let me know.