A/C doesnt work on HIGH setting


Thunderball
06-24-2004, 05:04 PM
The A/C switch on my 2000 Chevy Astro only works on 3 of the 4 settings.. HIGH setting doesnt work about 99% of the time. Every once in awhile it will work, maybe once every 3-4 months. What does this mean? I have replaced the fan, this didnt make any difference. I replaced the A/C switch, this didnt make any difference. Now its summertime in Florida, the temps are rising, and I NEED to use my A/C on HIGH. I donot have rear A/C! I am at the end of my rope, does anyone out there know what could be the problem?! :uhoh: PLEASE HELP! :uhoh:

FCFFUZZYFACE
06-24-2004, 07:54 PM
the high blow function goes through the switch but does not go directly to the blower motor, the switch energizes the high blow relay, sounds like you have burnt contacts in the relay, you could have a wiring problem but the relay would be my next guess

FCFFUZZYFACE

Thunderball
06-24-2004, 09:50 PM
Where is the high blow relay located? I'd like to check it out. It was quite a procedure just getting to the switch. Thank you for your reply!

Deadcarny
06-26-2004, 11:24 PM
mine does the same. i replaced the blower relay and the resistor and it still does not work on high (but now the other speeds work)

Thunderball
06-26-2004, 11:28 PM
mine does the same. i replaced the blower relay and the resistor and it still does not work on high (but now the other speeds work)


Where is the blower relay and resistor located? Id like to check that out. Thanks for more info.

Thunderball
07-01-2004, 09:42 AM
Does anyone know where I can locate the blower relay? Is it under the hood or within the dashboard? Im still trying to figure out why my a/c doesnt work on HIGH. Any information is appreciated, thanks

gptunah
07-03-2004, 08:06 AM
I had the Heater/ Air panel (on dashboard) out the other day and could see that it uses an extra vacuum line for the MAX setting. Is it the same for the 2000 model (mine is a 1995)? If that is loose or unplugged, I don't think it will work.

Thunderball
07-03-2004, 09:25 AM
I had the Heater/ Air panel (on dashboard) out the other day and could see that it uses an extra vacuum line for the MAX setting. Is it the same for the 2000 model (mine is a 1995)? If that is loose or unplugged, I don't think it will work.

The dashboard on the 2000 Astro (see below) is totally different than the 1995. Im having trouble when trying to use the lefthand blower switch, it doesnt work on HIGH setting. Ive replaced the switch plus the fan and it didnt make any difference. Thanks for the reply.


http://bellsouthpwp.net/r/m/rmdelong/2000astropanel.jpeg

gptunah
07-03-2004, 02:59 PM
I looked back over the replies to your question and have to agree with FCFFUZZYFACE. It sounds like burned or dirty contacts on a relay, or a loose connection (maybe a loose plug/socket, or a wire connection to the plug or socket). The fact that it did work a couple of times would indicate this. I don't have a good manual yet. The Haynes manual I bought is okay for simple stuff, but the service and repair manuals go into better detail. The picture in the Haynes manual for your van shows a relay/fuse box under the hood between the battery and the powersteering reservoir. You might look there. I had a 93 escort wagon a few years ago that had a similiar problem. every time I gave someone a ride, the heater would stop working on some of the fan speeds. I got under the dash and found a loose plug with 4 or 5 wires going to the fan. I tightened it up and it all worked fine after that.
I'm trying to figure out why my air doesn't work at all right now. The compressor doesn't even kick in and the Haynes is a bit vague. I'm just starting to look into it though, so if you have any ideas....

Thunderball
07-04-2004, 05:28 PM
I found the fuse box and opened it up, and saw a diagram in the lid of what each fuse is for. 4 were labeled a/c. Since there were spare fuses in there, I switched each ac fuse and tried the HIGH setting. Nothing. I pushed in each fuse in the box in case anything was lose. Nothing. But thank you for the response, I need all the info I can get, I'll try anything. Was there any other info in the Haynes manual regarding the ac? Im trying to locate something that would show a diagram of the ac system. Thank you for your response to my problem!

:)

What vehicle do you have now that the ac doesnt work? Is it an Astro?

gptunah
07-04-2004, 08:14 PM
A 1995 AWD. I bought it last fall. It's great in the snow (Maine) and better on gas than the 95 pickup. I checked it today and am getting around 18mpg combined highway/city driving. the pickup averaged around 13. I'm working at tightening up the vacuum system to get it running a little smoother. I got an a/c charging kit and freon today and charged up the system. it works fine, but at the end of the day it is cycling more than it should so I know it may be low on freon already. next step will be to get a can of the green stuff into it and check it out with the special glasses to see where the leaks are. I spent some time this morning looking through the postings and found some great stuff on working with the a/c and also brake work. I'll spend the money to get the best parts. I realize that it doesn't make much sense to put my life on the line to save a couple of bucks. I'll check out the manual again tonight to see if it has the a/c system diagram. be back in the am.

joeval
07-07-2004, 01:37 PM
The connection for the blower fan is located at the blower fan behind the coolant tank and winshield wiper tank. You need to remove the tanks (it has 2 pins that pull up at the middle). Remove the connector and check to see if it is lose. I had the same problem and I just pushed closed the connector (the thickest wire since it is the highest setting) and reconnected. If it doesn't work, make sure that there is current in that thick wire when you set it to high.

Thunderball
07-11-2004, 10:01 AM
YESSSSS it worked!! I checked the connectors in back of the blower fan, and although none didnt seem to be loose, I pushed them all in anyway.. and then I checked inside to see if HIGH was working, and to my surprise, YES it was working! :evillol: Woooo Hoooo!! About 2 days later it quit again, and this time I knew right where to look. It seems the one connector doesnt fit as snug as the others. :screwy: I want to THANK YOU ALL! for sending your suggestions and advice!!! :grinno: This forum is GREAT! I hope I can help someone in the future. Lee

ggcatt
07-12-2004, 01:13 PM
Thanks for the info. I had the same problem with my 1992 Astro, the HIGH blower setting was dead, all other three settings worked fine. I traced the problem to the blower relay, located just above the blower moter on the passenger side, just under the hood. It's the bigger of two relays, the other might be the fuel pump relay? Anyway I pulled the blower relay out and found that the contacts werent' closing when the blower switch was placed into HIGH position. Had good contact with the other three positions. But, then I screwed up. I tried to "bend" the relay contacts closer together (with the blower switch and ignition key on "off"). SURPRISE-SURPRISE-SURPRISE, there was much smoke and sparks, Apparently this relay is energized all the time. Should have disconnected the battery. Now, the relay is toast, need to get a new one. The first three blower settings still work, so I'm no worse off. Anyway, I THINK this fix would have worked, had I disconnected the battery first......

engfoxhound
08-02-2004, 10:17 PM
I have a similar but very different problem. My climate control ONLY works on high, and the a/c stays on all the time. I can turn it to vent, heater, blend etc and the a/c runs. I'm not turning the a/c it's just always on now, and only blows out of the vents. It's a 1994 rebuilt POS... I don't have a clue what you guys said in previous posts on this thread, I don't know any car lingo. I'm blonde and female, no car sense, so please speak in cars for dummy lol.

joeval
08-03-2004, 12:19 PM
Your problem sounds familiar fox. The switches at the panel usually corrode or get very dirty so they make contact all the time so the a/c stays on. It would have to be taken apart and cleaned which takes some skill because there are some small parts to it. It could also be rigged by connecting a switch to operate the a/c compressor. Much easier to do just the inconvenience of an extra switch.

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