BadGTho

iTrader: (6)

Sorry if this is the wrong section.... but i have no idea where else to post.

here's the deal... when i turn on the a/c the compressor will not kick on. i've checked the A/C - Cruise fuse and swapped the a/c - comp relay with the fuel pump relay.. the car still runs... so i know that's good. when i spin the compressor by hand, it spins. i also ran a test light down to the compressor... nothing.

not 100% familiar with GM a/c... could it be a low refrigerant issue? not allowing the pump to turn on to keep it from burning up? there's definitely stuff in there, i checked the press-valves.

what do i do???

the car is a 98 t/a

RE AND CHERYL

iTrader: (31)

Just because there is some pressure in ther dosn't mean there is enough. Most likely it's low, especially if it worked last summer. get it serviced.

Re'

BadGTho

iTrader: (6)

Ok thanks.

so are you saying that there is in fact a low pressure switch? whereabouts would it be? i'd like to bypass it to confirm that this is the issue.

Texfinn

iTrader: (39)

Yes, if there is not enough refrigerant, the compressor will not kick on.

Not sure where the switch is, though. I guess I could get off my *** and go to the garage to check my Helms manual, but...

EDIT: Here you go. Picture is from LT1, but I think it is in the same location also in LS1's/

bww3588

iTrader: (49)

that is the high pressure switch.......it makes it kick off when pressure gets too high. i think the low switch is down by the condensor behind the radiator.

FiredUpZ28

When you fill systems that are too low for the compressor to kick on just jump the low side until the system is above threshhold.

bww3588

iTrader: (49)

or put it in a vaccum for 30 minutes so you get all the **** out of the system. when you do things right, **** tends to last a whole helluva lot longer.

BadGTho

iTrader: (6)

thanks for the great info guys.. i will poke around tonite and see what i can see. i'm assuming that the low pressure switch looks much like the high pressure switch.. right>?

is that a likely cause for the compressor not kicking on?

Jon5212

iTrader: (2)

There should only be 1 switch in the system AFAIK. Which is the low pressure switch. Sounds like you probably just have a slow leak and there is not enough refrigerant in the system to kick on the compressor. I'd grab an A/C gauge and see what the pressure is. I'm not sure what the normal pressures are though.

BLACK2001SS

Not always its a trubble shooting game with AC systems.
But first you have to charge the system to find out. If it dosent take a charge then you track to see if your compressor is working and your pressure switches. It may also just be the switch in the dash.
First things first Charge the system.

BadGTho

iTrader: (6)

as it was in my old yota pickup.. what a nightmare... ughhhh... all i want is some f-ing A/C!

i am going to start tonite by jumping the pressure switches.. if the compressor kicks, i'll assume that it's low and i'll get a charge.

if it does not kick, i'll probably seek professional intervention.

BLACK2001SS

Yeah I feal ya I've installed several ac system and have seen every problem thier is just about and I take my car to the shop just so I can take it back. In the end spending all the cash on fixing my problem myself and then only to find a leak somewhere, it would have been cheeper in the end just to take it to the shop.

BadGTho

iTrader: (6)

yeh.. i hear ya.

i don;t have gauges, and i do have electrical knowledge, but not terribly specific to the functions in the dash.

if my simple trouble shooting, testing can;t yield an answer... i'd rather have someone else just tell me what it is.

bww3588

iTrader: (49)

if you dont have manifold gauges, i wouldnt mess with it. there is no way to tell exactly what is in there, or if there is anything in there. if you jump that switch and there is nothing in there, your going to fry the compressor. you may only have it on for a second, but it doesnt take much.

what i would do in this case, against my better judgment, is buy a can or 2 of the R134A **** from autozone and see if you can get it to kick on that way, if it does, you got a leak and need a recharge and something fixed. if it doesnt kick on, you got an electrical problem somewhere. dont just assume the system is empty if it kicks on when you jump the switch, cause it might be full just an electrical problem keeping it from kicking on. then you take it somewhere and pay someone to tell you your system is full, and your back at square 1. and you still have to have it recharged after you repair the problem, if its a compressor or one of the pressure switches.

*TAKE IT SOMEWHERE TO HAVE IT RECHARGED*

i cant stress enough how terrible of an idea it was to put refrigerant in cans on the shelf at autozone. this is where the majority of peoples problems come from. the bad thing about these is, is there is no way to tell if the system is full or not, if you run it low, when conditions change its going to change pressures and not run right, and visa versa. each system takes a specific amount of refrigerant, not to mention oil that the compressor needs, which does not come in thoes little cans.

BadGTho

iTrader: (6)

i understand. i pressed the valve.. there is definitely something in there.. for sure.

i just want the thing to kick for a second.. then i'll know if either switch is the issue.

Jon5212

iTrader: (2)

Each car has a sticker that says how many lbs of refrigerant it holds. I've never had a problem recharging my own. I have manifold gauges and my dad has a vacuum pump. It's pretty simple process... the AZ stuff is perfectly fine. They have the oil in a can as well. But to the OP if you are not comfortable doing this there is no problem in taking it somewhere to have it done professionaly.

BadGTho

iTrader: (6)

what does an a/c recharge/evaluation tend to cost?

bww3588

iTrader: (49)

i *think* i remember seeing it going for around 89.99 or so last summer. i cant say for sure tho. that may have been something else.

sreve

iTrader: (3)

what bbw3588 said.
bad idea with out guages and someone looking at them that knows what they are looking at. i have worked on cars that the compressor would not stay running and i put guages on it and found out it was way over charged with a wal-mart death kit. (dangerous)
your a\c system only holds 1&1\2 pounds of freon the low side switch cuts off the pressure at about 25psi it does not have to be very low for this to happen with a pound and a half total capacity.
heres how it happens the death kit is a pound can liquid to the low side the compressor sucks it right in and it does not cool for **** it and it won't if it's overcharged it must need another can more is better.

FastB

iTrader: (11)

Just had mine checked last week. $123 when it was all said and done. This was a complete system check and re-charge.