I have just purchased a 99 SSEi, loaded to the gills. Bought in FL, drove it 750 mi to MD with no major problems. 2 wierd things happened, though, and I was hoping someone could shed some light. About 3/4 of the way through the trip the low coolant light came on, didn't stay on, came and went a few times. I stopped and checked and level in the res was right on the full hot line. After getting it home and cooling off (the next day), res level right on the full cold line, rad filled to the cap. Bad sensor, maybe?

Next hiccup. When I stopped to check the coolant level, I noticed that the A/C lines and the cannister thing on the firewall (drier?) were completely coated in ice. Temps were in the upper 40'* and low 50'* the whole trip, CC on Auto. Is this a problem clue or normal ops? I read in the manual that the compressor runs continuously under 40, seems a bit odd to me. Any insights appreciated.

Thanks,

For the coolant issue, I had that exact same thing. It was an electrical thing. Coolant was fine.

Yes, they have a little reputation for doing that.

I'd call it normal. They're colder than atmospheric temperature, condensation builds up on them, and on a chilly-enough day, it'll freeze. As long as it'* just frozen on the outside, it'll do no harm; in fact it'll help the heat exchange.

Can you give us a page reference on that? Normally the compressor does _not_ run (at all) around 50º F or lower (or 49º, depending on which page of the '93 manual you look at); a temperature sensor blocks it from doing so to prevent internal damage.

Looking at the 1999 Manual, page 3-6, right column, 2nd paragraph.

"When the air conditioning system is in AUTO mode, the
A/C light will always be on. When the ambient
temperature outside the vehicle reaches 40
F (4
C), the
compressor will remain on continuously."

Strange wording there. But I assume that "reaches" in this context means "is as high as," not "is lower than." Like you said, it would make no sense to only run the compressor continuously _below_ that temperature, unless there'* some useful property of R134a refrigerant at that temperature that I'm not aware of. (The '93 used Freon/R12, not R134a.)

Fuddy?

I am thinking that the A/C may possibly be overcharged. Need pressure levels, especially the high side.

Well, here is my experience with A/C systems. I have a brother and brother-in-law who are certified A/C repairmen.

On 95% of automobiles when you acivate the DEF system to clear the window of frost/fog the A/C compressor will kick on. There are two reasons for this.

1. It helps remove moisture from the air to help more efficiently clear the fog from the window. You dont want moisture being thrown at the window that you are trying to remove moisture from.

2. It helps keep the oils in the A/C system moving so it does not become sedate and go 'POOF' in the spring when first activated.

I know from my dad owning (4) GM Products with ACC (Automatic Climate Control) that the A/C compressor is engagued in DEF and AUTO modes.

Same goes for my 99. (Unless I take the A/C off in AUTO mode).


Hope this helps.

Jay

To tell the truth, I wish my '93 had the float design, because I could fix it. Instead I've got the plug-in sensor that goes in the side of the radiator, has no moving parts and likes to give false alarms a lot.

Was there really a problem with the A/C here? I thought the question was whether ice on the outside of the plumbing was unusual (under the right circumstances I don't think it is unusual), but I don't remember reading about having the A/C stop blowing cold air at any time.