[DMCForum] Re: A/C Question

["cruznmd" <racuti1@xxxxxxxxxxxx>]

Dave,

Most of what you said was Greek to me, but I do have one suggestion;

Run the car and A/C. While it's running put an ohm meter on the low 
pressure switch contacts. This may be difficult with the electricals 
hooked up to it. Use paperclips or something to get meter 
connectivity while the plugs are on it.

See if the low-pressure switch stays closed all the time, or if the 
system keeps running even when the switch is open. That should lead 
you in one direction or the other.

If the switch cycles, but the compressor runs continuously then I 
can't exactly tell you where to look (I'll bet you know) but if the 
switch is constantly closed, then either it's faulty or something's 
up in the system to where you never get up to pressure for the switch 
to open.

You could also "manually" switch by removing a contact wire from the 
low pressure switch during operation and see what that does.

Hope this helps,

Rich A.


--- In DMCForum@xxxxxxxxxxxxxxx, "Dave Stragand" <dave.stragand@xxxx> 
wrote:
> Hi All,
>  
> I hooked up the A/C today, evacuated it, and charged it up.
>  
> I evac'ed the system for about 90 minutes, at 28" Hg, then charged 
it up.
> The low side pressure is at 32, the high side at about 170-175, and 
the temp
> today was about 75 F.
>  
> The system is blowing pretty cold (though not sure how cold, as I 
cannot
> find my A/C thermometer anywhere) but the compressor isn't cycling -
- it
> just runs continuously.
>  
> Following the checklist in the workshop manual, it says to check 
for missing
> expansion tube (it's in there, and it's new), or that the system is
> overcharged.  Considering it only would take about 28 ounces of 
R12, and the
> service bulletin calls for 36 oz, I don't think it's overcharged.
>  
> (I do have one known small leak, on the Schrader valve on the low 
side hose
> at the compressor.  I'm going to see if I can track down that nifty 
little
> tool that allows you to change it without evacuating the A/C.  For 
now, I
> have a plastic o-ringed sealing plug on it to help slow the leak.)
>  
> I did have a problem where the back of the high-pressure cutoff 
switch came
> off while I was mounting the high side hose, but it snapped back on 
without
> a problem.  The low-pressure switch is new.  Could that be the 
issue?  Or
> does anyone have any other suggestions as to why the compressor 
will not
> shut off?  
>  
> -Dave
>  
> 
> 
> [Non-text portions of this message have been removed]

Yahoo! Groups Sponsor

ADVERTISEMENT

---

Yahoo! Groups Links

• To visit your group on the web, go to:
  http://groups.yahoo.com/group/DMCForum/
   
• To unsubscribe from this group, send an email to:
  DMCForum-unsubscribe@xxxxxxxxxxxxxxx
   
• Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.