Dead AC...

[Bonzo22]

I have a '96 Eddie Bauer w/ 5.0 liter engine. I was using my AC today and the setting was on Max. It was working fine, I turned the blower on low for about five minutes. I turned the blower up high because it was getting warm inside the cab. I then noticed the air was staying warm (not hot). Could I have lost my charge in that short amount of time?

When I got home I immediately opened the hood and had my son turn the AC on and off a couple of times. I can hear a load change on the motor when the AC was turned on. I changed the AC to heat and that works fine. Please note that I have a computer environmentally controlled unit.

Should I try to recharge the AC before moving on to further steps? What further action can I take if charging fails?

Thanks for any advice you can give me.

[shorod]

You should start by performing the self test on the HVAC system. The process to do so has been posted before, try the "Search this forum" feature from the Explorer forum main page. A decent keyword to search on may be "EATC."

As for charging the AC system, overcharging could also cause what you describe, so don't just hook a can up and put more R-134a in. When you son turned on the AC did the compressor clutch engage? Just going by a change in engine speed isn't a sufficient check.

-Rod

[Bonzo22]

Just got back from a long vacation. My AC worked fine the following day so I didn't look into it any further. Well, just two days ago (7/24) it finally decided to quit.

I looked under the hood and saw the compressor clutch is not engaging. I will investigate further tomorrow. I have a lot of yard work to catch up on today so I will be able to dedicate some time for the AC tomorrow.

Thanks for the reply.

[Bonzo22]

Ok here I go

I was able to get the compressor clutch to engage when I jumped wires directly to the battery. Cold air blew out of the vents. The ohm reading was a 3.8 on the compressor. I received 11.7 volts at the connector. When the connector is plugged into the compressor I hear the relay click on and off inconsistently. I swapped the relay and got the same results. Would the low pressure sensor cause the relay to act like this when a signal is sent to the computer? I do realize that when I forced the compressor on that I still may have low pressure in the system.

I tried jumping the low pressure sensor but could not get the compressor to kick on. (Is the low pressure sensor near the compressor or the accumulator?) I tried jumping both with a paperclip and was unsuccessful. I would think that jumping the low pressure sensor switch can get the compressor to work.

I have been trying to find somebody with some pressure gages that I can borrow. I would like to know what the pressure is before I venture any further.

[shorod]

Good thought on getting a set of gauges on there and measuring the high and low pressures before proceeding. Sounds like it may just be a pressure issue, but it is odd that jumpering it didn't cause the compressor to engage. The low pressure switch would be the one near the accumulator.

-Rod