faulty air conditioner

[tapkoote]

I've got an 08 ranger with 56000 mi.
Twice now the air conditioner came on for an instant, then nothing, just cabin temp air.
I had the blend door replaced at 36, 000 mi.
I wouldn't think it would be that.
acts like a bad relay or maybe a bad temp sensor.
If so where do i look?
Thanks for any help.
Pat
PS 2 whldrv 6cylinder

 

[blacksnapon]

Still waaaaay too many things that can cause your issue. High/low pressure cutout switches, low freon levels, short to ground/power, bad clutch/compressor,etc.

 

[tapkoote]

Here's a new twist on it.
This afternoon after sitting in bumper to bumper traffic, it came on and stayed on. I flipped it to AC and Max AC and it still stayed on, like normal. Even shut the truck off once, and it came back. ???????
Is it sleepy from a long winter, I was told these are supposed to cycle once in a while ever in winter.
Could it be the humidity sensor?
The defrost took longer this winter than before.

 

[tapkoote]

The thing went out again this morning.
I read through my Chiltons manual, and searched threads here.
Tested the fuses in the passenger , and engine compartments.
Pulled the WOT relay, it doesn't have a wiring diagram, like the old ones, does anyone have a diagram how it's wired?
This being intermittent, I'd guess it could be this relay.
I don't hear the clutch kick in, it's not frozen.
When I idle the truck and flip on the AC, the idle goes up for a few, but drops when no clutch kicks in.
Being retired, I hesitate to invest in the shop time, if it's something I can fix.
Thanks for any help.
Pat

 

[blacksnapon]

Is the compressor clutch engaging constantly? Or does it disengage when the a/c quits?

 

[tapkoote]

Right now the compressor isn't running at all.
It does spin by hand.
I tried to find the ground lug on it but both posts read open
to batt. neg.
thanks Pat

 

[dustybumpers]

try checking the wires to the low pressure switch, right there at the expansion tank.

When it was running, was it functioning normally?

 

[tapkoote]

Thanks
yesterday it seemed to run normal, about 1/2 hour.
I'm not sure what the expansion tank looks like, the chiltons doesn't point it out.
By checking, do you mean look for corrosion, or for continuity.

The plug on the low pressure switch looks OK, is that a place for some dielectric grease?

 

[dustybumpers]

On your heater box, under the hood, there is a black "tank" with the a/c lines coming out of it, on one of those lines is a 2 pole switch. That is the low pressure switch, check for power there.

But.... If it worked well, for a bit, I suspect you are ok there. I think maybe the contact on the switch in the dash is bad. Try on Defrost, and see if the compressor kicks on.

 

[tapkoote]

Thanks again dusty
the multimeter said 97 millivolts.
When I plugged it back in the idle went up but the clutch never came on.
Pat

 

[dustybumpers]

Did the compressor come on set to defrost?

 

[tapkoote]

it wont come on at any setting.
I was going to jumper it, but both poles are open to ground.

 

[dustybumpers]

Put it on A/c. remove the wires off the switch I told you about, and put a paper clip in the harness. It should fire up the compressor.

DO NOT RUN IT LIKE THAT

This is only a test to see if you have enough freon. If the compressor comes on, you will have to have the system charged.

 

[tapkoote]

tried it twice, that didn't start the compressor.

 

[tapkoote]

well I did find the diagram on the relays
the two small one checked out differently
when I switched them the truck wouldn't start.
I'm headed to Ford for a relay tomorrow.
Thanks-I'll let you know.

 

[tapkoote]

WAHOO
It was the WOT relay, $15.95 at the dealer.
I'd like to thank Charlie, he saved me my $100
deductible on my extended warranty, being retired
thats a lot.
Now I'm a little more familiar with this system, another question. I watched a vid on how to test high and low vacuum, but don't see any ports on this system.
How is it tested?
Not Sweaty in Seattle
Pat

 

[dustybumpers]

You need gauges to test the system. I highly recommend that be done by a licenced pro, there is a good possibility of you becoming seriously injured when tapping the high side improperly.

As long as it cools properly, just roll with it. When the compressor starts kicking in and out frequently, let me know, and we'll tackle that bridge when we come to it

You are welcome!!!! That's what we are all here for, to help each other out