ac cycling on/off at weird intervals

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

inetquestion - 02 Jul 2006 15:40 GMT

I'm having problem with the ac on my 1998 ford explorer cycling on/off
at weird intervals. My first thought was that it had leaked and was
low, but after buying a gauge it was found to be in the middle range of
"full". Sometimes it will cut on when I first get in the car and may
run for an hour or more. Other times the compressor may not engage
until I've been on the road for an hour or more. After that it seems
to come and go as it pleases. A friend suggested it may be the
pressure sensor on the low side, so I tried to by pass it. Jumpering
the two wires did not cut the compressor on as I had expected. This
lead me to think maybe there was a short in the clutch circuit or
possibley a loose wire. However inspecting it found no problems. Are
there any other sensors which I should check? Is there any reason why
jumpering the low side sensor did not engage the clutch? As a side
note... when the ac is on it cools normally. This confirmed my gauge
findings that the coolant was at the right level.

-Inet
--------------------
http://www.69camarorestoration.com

Reply to this Message

jeffcoslacker - 02 Jul 2006 16:26 GMT

Gauge doesn't show full or low, it shows pressure in the system, and you
are only looking at the low pressure side. It sounds like the charge in
the system is very low, or you have a roaming blockage that is causing
it shutdown sometimes due to excess high side pressure (I think you
have a high pressure switch as well)

I'd get it looked at professionally, if you have a blockage and you try
to charge it, you might explode a hose or core....

Signature

jeffcoslacker

http://www.automotiveforums.com

Reply to this Message

inetquestion - 02 Jul 2006 18:15 GMT

I made a mistake from earlier testing. bridging the low side pressure
switch does keep the system on. replacing it for $10 seems to have
worked.

Reply to this Message

inetquestion - 05 Jul 2006 21:38 GMT

The rest of the story is the shorted out wire on the drivers side of
the car. The low pressure switch wire was in a bundle of wires that
came out of a larger bundle. The smaller ones were on the bottom and
were rubbing against the inner fender well. Eventually they rubbed
through on the wire for the low pressure switch. Once this was
cut/spliced the problem was gone. My first guess of the switch was at
least in the right direction of an electrical problem. Howerver when
jumpering it produced mixed results I should have immediately began
looking for shorted wires. Oh well...its working now. :)

Reply to this Message

Kevin - 05 Jul 2006 22:01 GMT

> The rest of the story is the shorted out wire on the drivers side of
> the car. The low pressure switch wire was in a bundle of wires that
[quoted text clipped - 5 lines]
> jumpering it produced mixed results I should have immediately began
> looking for shorted wires. Oh well...its working now. :)

Thank you for reporting the fix to us. So few ever do.

Signature

Kevin Mouton
Automotive Technology Educator
"If women don't find you handsome,
they should at least find you handy."
Red Green

Reply to this Message