A/C Shutting Down.........

[Tbar]

A/C clutch seems to have a mind of its own. Seems to disengage occassionally, mostly at lower engine speeds.

When it shuts down I can rev the engine and it will re-engage.

When it is working I get 43 degree air which is a little bit down from the normal 39-40..........but then it is really HOT outside.

So what could this be...........a bad high/low pressure switch or something??? Does it just need freon? How do I figure it out?


Tbar

 

[JLDickmon]

honestly, without knowing the pressures in the system it's really difficult to tell...

it may in fact be a power steering switch locking it out for what it thinks is high engine loads...

don't run out and replace the p/s switch (I mean you could, it's a relatively cheap guess)... buy a set of manifold gauges or take it somewhere.

 

[whatabudro]

Its the noisy torque convertor

 

[JLDickmon]

Its the noisy torque convertor

might need to recalibrate the torsion bar on the riboflavin injector, too..

 

[Djracer]

Mine does the same thing and both my local gurus say its the clutch getting weak!

 

[Tbar]

Measuring voltage at the battery:

Engine off: 12.6 volts
Engine @ idle: 12.7 volts
Engine @ 2200 rpm 13.2 volts
Engine @ 2200 rpm with lights and a/c on 12.8 volts

While not great these voltages are still above 12 volts. Wouldn't this be enough to operate the a/c clutch?


Tbar

 

[Big K]

Lance,

This is a quick meathod to deturmine the R134a Level if you don't have a Gauge Set (a Gauge set can be loaned out from Autozone, just FYI)

On vehicles that are not equipped with sight glasses, it is necessary to feel the temperature difference in the inlet and outlet lines at the receiver/drier to gauge the refrigerant level. Use the following procedure:

1. Locate the receiver/drier. It will generally be up front near the condenser. It is shaped like a small fire extinguisher and will always have two lines connected to it. One line goes to the expansion valve and the other goes to the condenser.
2. With the engine and the air conditioner running, hold a line in each hand and gauge their relative temperatures. If they are the same approximate temperatures, the system is correctly charged.
3. If the line from the expansion valve to the receiver/drier is a lot colder than the line from the receiver/drier to the condenser, then the system is overcharged. It should be noted that this is an extremely rare condition.
4. If the line that leads from the receiver/drier to the condenser is a lot colder than the other line, the system is undercharged.
5. If the system is undercharged or overcharged, have it checked by a professional air conditioning mechanic

 

[Tbar]

Thanks Kevin.

Also, do our trucks have intake filters and if so where..............???


Tbar

 

[Big K]

Ya mean Cabin Filters???


And Yes, I believe the Super Duty's Do.

 

[JLDickmon]

cabin filters - some do and some don't.

mine, for instance, has a listing for it in the parts catalog, but it does not have one in the location specified...

if the vents smell like dirty gym socks, it probably has one and needs to be replaced. Both filter manufacturers I use call for yearly replacement. I've taken some out that had mushrooms growing in them...