A/C help

[Rasputin]

A/C is blowing warm air out of all vents. Checked sight glass and no foam/bubbles present. Expansion valve or whatever the silver thing near firewall with 2 lines going in is cold. Clutch on compressor engages but can't hear it cycling on and off, which it should be doing, right? Could this be a blown fuse, bad relay or something? A/C worked well all last summer ....and now it looks I might be part of the 90 mph/with windows down club.

 

[01xj]

As annoying as it is - yes, it should be audibly cycling. Mine makes
quite an annoying clicking sound with each cycle.

I'm still learning about the XJ HVAC system (there's quite a bit in
the FSM), but I would start with a fuse or look for an OBD error
code that could point you in the right direction.

The system seems overly complicated to me - but whatever.

Good luck.

 

[RichP]

What year, if you have a sight glass it sounds like it is an old system, R12 style. If the low pressure side is ice cold and sweating you should be getting cold air, if the high pressure side is too hot to touch then your freon level may be too low. Check your temp control, it uses a cable to control how much cold/hot mix. It could have come off.
On the new R134 style the manual says that if the compressor cycles more than 5 times in one minute with the system on max cool with fan on high you have low refrigerant. Should be similar to the older systems.

 

[Rasputin]

I'm going to check the cable on the temp control. Once my compressor comes on it doesn't cycle. Thanks for the help.....

 

[RichP]

I knjow the compessor clutch is making noise, but is it coming on and is the clutch spinning or is it just coming on momentary and the off just as quickly ??

 

[Rasputin]

The clutch is spinning and stays on without cycling. Today I noticed where the lines go into the firewall there was a lot of condensation...dripping. Is this normal or is this my problem(leak)?

 

[Rasputin]

Jeep is a '91 and still using old R-12.

 

[MJR]

If the suction line at the expansion valve is getting cold then it sounds like a temp door/cable or maybe evap problem. I can appear like there is no air bubbles also if it is low enough that it's all air at the sight glass.

 

[Rasputin]

Yabba dabba grab a brew.....thanks for the ideas on what to check on. Should keep me busy over the holiday.

 

[RichP]

If you have condensation and the line is ice cold then the compressor and ac are working. Really sounds like a mix problem with the flapper in the interior box. does moving the temp handle change the temp at all ??

 

[Rasputin]

Moving the temp control does change temp. Right now it's blowing borderline cool/luke warm when set at max. Is the flapper that vent near the passenger side door? If so, I've checked that and it's totally open when set at max.

 

[01xj]

Moving the temp control does change temp. Right now it's blowing borderline cool/luke warm when set at max. Is the flapper that vent near the passenger side door? If so, I've checked that and it's totally open when set at max.

Not too familiar with the R-12 system, but I noticed the newer
FSM shows a "blend door actuvator", and a feedback signal
coming back from the PCM. If you have a solinoid in there - I'd
take a peek at that. Maybe it's sticking or not getting the
feedback signal.........?