AC not working *solved* Low pressure switch bad

Rockrz · Post by **Rockrz** » Fri Feb 29, 2008 5:30 pm

Well, it may not be my compressor after all. Before jumping into projects like AC repair, I always like to check the basics, like checking to make sure the compressor is getting juice...and it's not!

So, I checked my fuse, and it's OK...so, since I have to drive the truck and I've not changed it in the almost 7 years I've owned it, I'm going to go ahead and get a new AC Relay.

I see that it should be one of the 4 relays under the hood on the passenger side on the firewall right above the distributor.

Does anyone happen to know off hand, which one of these is the AC Relay???

Edited title-HJ

Post by **HenryJ** » Fri Feb 29, 2008 5:53 pm

Have you checked the low and high pressure switches?

Rockrz · Post by **Rockrz** » Fri Feb 29, 2008 6:34 pm

No, I'm going to do that tomorrow when I have time to spend looking at more items.

I'm just happy at this point that the compressor isn't getting juice cause that means all that's wrong is probably just something electrical.

I'm going to check several things tomorrow to see if I can pin point exactly why it's not getting juice.

All I did today was pull the plug in off of the compressor and test it with a test light, which is how I found out there was no juice to the compressor.

Post by **HenryJ** » Fri Feb 29, 2008 8:25 pm

The high pressure switch on the back of the compressor will be powered when the dash switch requests the AC. Then if the this switch has continuity it will allow the low pressure switch power. If there is sufficient pressure in the system this switch will have continuity and it will allow power to the clutch for the compressor. That may be way simplified, but those are the components I would check first.

Rockrz · Post by **Rockrz** » Sat Mar 01, 2008 7:34 am

Yep, later this afternoon I'm going to get out there and check all of these components to try and pin point why there no juice to the compressor.

Rockrz · Post by **Rockrz** » Sat Mar 01, 2008 4:30 pm

Well, good newz...it was the low pressure cut off switch on the drier.

I spent about $11.00 for a new one and the AC worked perfectly all afternoon as I went out driving around doing errands.

$11.00 sure beats several hundred dollars!

Thanks for all the tips and ideas.

Post by **HenryJ** » Sat Mar 01, 2008 4:37 pm

Good deal. Where are you that you need AC, when we are still freezing nights here?

Rockrz · Post by **Rockrz** » Sat Mar 01, 2008 4:46 pm

HenryJ wrote:Good deal. Where are you that you need AC, when we are still freezing nights here?

Texas!

About the last couple of weeks it's been nice in the AM, but about noon I need my AC.

Mainly because riding around with the sunshine coming in warms up the inside of the truck making it just warm enough to want to turn on the AC.

During the spring, summer, and fall....I pretty much never turn my AC off as it's always pretty warm down here.

You guys should see how funny people get if we get a little ice or snow...the peoples be
all freakin out like the world is coming to an end, or something. It's pretty funny.

roadrunner · Post by **roadrunner** » Sat Mar 01, 2008 5:38 pm

HenryJ wrote:Good deal. Where are you that you need AC, when we are still freezing nights here?

Kinda feel sorry for you fellas in the heavy snow belt. Okay I'm over that already.

Got up to 80F here today. Supposed to be cool next couple days though. Only up to 40 or so and down to 20-25 at night. almost no snow here this year or rain either for that matter.

quickbiker · Post by **quickbiker** » Tue Jul 15, 2008 7:34 pm

I was just going to post on the same resolve for my A/C and saw this thread. Mine was the same thing, low pressure switch. Got it for $25 from rockauto.com part 1550104 (15-50104) for 2001 year anyhow. It was hard to trouble shoot till it was not working much. Seems when it was intermittent and working mostly, it always worked when I wanted to trouble shoot it. So anyone has intermittent probs and pressure is good, it pays just to change the switch out. No lose in freon, cause it's on a shrader valve. It still doesn't matter much to me since I ride my bike mostly in the summer, but it sucked when I had a truck full of people wheeling with no AC.

Rockrz · Post by **Rockrz** » Wed Jul 16, 2008 5:52 am

quickbiker wrote:...since I ride my bike mostly in the summer

C'mon, man! Ya gotta get out there and increase your carbon footprint so you can be like AlgoRe and release lots of emissions!

quickbiker · Post by **quickbiker** » Wed Jul 16, 2008 8:26 am

Hey, that's not funny, we may actually have to, to save the world from global cooling.

Global cooling.

Nice artical about the natural warming, cooling, warming, cooling and how reported through history.

And a Harvard study.

So, if gas gets cheaper, I don't mind burning more fossil fuels. It help the vegitation grow more virgorously also! So go green!

Yellow Hammer · Post by **Yellow Hammer** » Sun Jul 20, 2008 2:25 am

How does the low pressure switch come off and where did you find one for only $11.00? I checked NAPA, Advance Auto, and Autozone and they sell them for around $25.00. Thanks.

Post by **HenryJ** » Sun Jul 20, 2008 12:47 pm

Yellow Hammer wrote:How does the low pressure switch come off ..

Disconnect the electrical connector and it will screw right off. There is a schrader valve in the attachment point, so nothing will be released. You will probably need a wrench to break it loose. Tighten it carefully. You don't need much pressure to tighten it as most of it is plastic.

quickbiker · Post by **quickbiker** » Sun Jul 20, 2008 8:36 pm

Yea, be carefull. The seal is an o-ring on the outside of the thingydoo. So it only has to be finger tight, but prob a bit more so it doesn't come lose. It's all plastic, so probably breaks easy.

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AC not working solved Low pressure switch bad

AC not working solved Low pressure switch bad