AC overcharged?

[737jet]

Okay, despite all my bad luck with my Expy, I still love this thing. Here's the really odd thing. Last year I charged the AC system with that r134 stuff in a can and a gauge. Cool kit.

It worked for a year. Perfectly. Now it's summer so I decided to try my AC. Nothing. Must be needing a top off right?

I checked the low pressure side and it was in the red band. Past the orange warning band and half way into the red band.

How could it overcharge itself? When I refilled it last year I made sure it was in the blue (good) band.

Now I just want to know how to fix it. I expelled some gases out of the low pressure side to at least bring the band back to blue. Still nothing.

 

[mustangswan]

I dont know what year your truck is, but they all work pretty much the same. If you know where the a/c pressure cycling switch is (located on the accumulator, next to the firewall and has 2 wires going to it). The fastest way to check a A/C system is to unhook the switch and jumper the 2 wires (harness side) and trun on the a/c system and see if the compressor comes on/ engages. This will tell you if your Elec system is working correctly. Then let it run for 2-3 minutes and see if the air gets cold or feel the accumulator gets cold. If both things above happen, then the pressure cycling switch is most likly bad and is a common problem. There is also a high pressure cut out switch, which is not the same as the cycling switch. If your truck is a 97-02, the cycling swtich is pretty hard to see if your not sure what you are looking for, but is there. The accumulator is located next to the battery on the passenger side of the engine compartment where the low side pressure port is.

 

[737jet]

First off, props to

al3bqre almo7trf,

I love how your hacking had me running around in circles like a dog chasing it's tail.

Second, Thank you mustangswan for your quick reply.

I found where the accumulator is. It's right up by the firewall and it is also where the low pressure fill port is. There is wiring plug on the top of it. That I believe is the cutout switch. I'll jumper it tomorrow and see what happens.

Oh, and yes your right. It is in a very hard to reach and see spot. Right behind a bunch of wires.

I did find a high pressure line with a switch and port closer to the condenser/radiator.

the truck is a 98.

 

[green03]

the low side will show an over pressure when the system isn't running (the port that you charge).

Once the compressor is running then the low side pressure will quickly drop.

Hope this helps....
Matt R

 

[737jet]

I got it to work after I bleed a bit out of the High side port. I jumped both the High pressure cut off switch and the cycling switch. When the High pressure switch was jumped, the compressor kicked in.

Wanna have a funny read, you should check out what happens when you ask a dumb question on f150online.

http://www.f150online.com/forums/showthread.php?t=334421

 

[737jet]

Oh the reason this worked is not because I reduced the pressure in the high pressure side, I somehow tripped the switch.

Maybe it was gummed or just being Fubar

 

[braduardo]

What a bunch of nice guys on that site... Next time you have a problem with your truck, I recommend you go to school for a couple years, then get out and spend 5-10 years working in an auto shop. Once you have done that, you should be able to handle working on your truck. If you still have any questions, just shoot yourself.

Yep, a bunch of nice guys over there. And here I was going to sign up on that site.

 

[737jet]

Ah whatever right? Most people probably have worked with the same type of guys in there life at one point or another.

 

[thereason21]

lol @ brad ... gotta hate so called know it all ********* eh? next time im lost i guess i have to shoot myself too huh?

 

[XLTman]

I feel you 737jet i have been having bad luck with mine lately last summer i had my ac overhauled and a couple weeks ago i went to turn ac switch over it just blew outside air. mustangswan does this sound like a easy fix thanks