More HVAC trouble- Control panel?

Hi folks,

Well, it looks like my HVAC trouble is not all resolved. I have replaced the compressor, condenser, receiver/dryer, both hoses and all the pressure switches. The system was working great for a couple of months.

About a month ago I started noticing a hissing for a couple of seconds under the dash (heater box) and also could be heard under the hood in the same area (by the receiver/dryer). More recently I noticed the fan noise changes - gets louder for a short while - but seems more like it could be going into recirculation. Now, a few days ago, the compressor didn't engage when I started the engine. The next time it worked normally again. Today it was normal the first time I started it. The second time, maybe a half hour later after driving and shutting off and restarting, the compressor is not engaging again.

It seems to me if the refrigerant has been lost, the compressor just would not engage, rather than engaging intermittently.

My thought - HOPE - is that the control panel is at fault and I can just plug 'n' play in a new one. What do the gurus think?

Thanks,
Glenn

Check your pressures sounds like you've got a leak.

Dropped88 said:

Check your pressures sounds like you've got a leak.

Click to expand...

Thanks. Yes, I will do that (or have it checked by the folks who filled it).

However, a bit of new info... I started her up after supper this evening and still no A/C. I opened the hood to check the plug on the back of the compressor. I remembered it doesn't "click" into place like it should and there are quite a few road imperfections here - broken pavement, broken patches and potholes. I do miss most of them, but sometimes there is an unavoidable one here and there. I wondered if that connection was loose.

No, it was still solidly in place. Then I started pressing in the other plugs on the compressor. None of those were loose, either, but as soon as I touched the plug at the compressor clutch there was a big click and the clutch engaged. The plug didn't move that I could feel so maybe one of the wires in the plug needs redoing. I will see if I still have A/C tomorrow.

Oh, when it was working tonight it was good and cold. I will get them to look everything over with the UV light, too.

Cheers,
Glenn

slovcan said:

Thanks. Yes, I will do that (or have it checked by the folks who filled it).

However, a bit of new info... I started her up after supper this evening and still no A/C. I opened the hood to check the plug on the back of the compressor. I remembered it doesn't "click" into place like it should and there are quite a few road imperfections here - broken pavement, broken patches and potholes. I do miss most of them, but sometimes there is an unavoidable one here and there. I wondered if that connection was loose.

No, it was still solidly in place. Then I started pressing in the other plugs on the compressor. None of those were loose, either, but as soon as I touched the plug at the compressor clutch there was a big click and the clutch engaged. The plug didn't move that I could feel so maybe one of the wires in the plug needs redoing. I will see if I still have A/C tomorrow.

Oh, when it was working tonight it was good and cold. I will get them to look everything over with the UV light, too.

Cheers,
Glenn

Click to expand...

Definitely check that plug could be corrosion or pin fitment on the terminals

Dropped88 said:

Definitely check that plug could be corrosion or pin fitment on the terminals

Click to expand...

OK, I don't want to tempt fate, BUT here it is. I unplugged the compressor clutch, sprayed some contact cleaner into the female side (harness side) and plugged it back in. Then I unplugged it again and pried the terminals toward the middle of the plug just a bit - less than a mm.

That was a week or so ago. I haven't driven her more than a handful of times since, but the compressor clutch engages every time now.

Cheers,
Glenn