My A/C or cooling fan will not come on. The fan will not come on at 230 either. Here is what I know/have done....

Blower works at all speeds
Replaced temp sender 6 months ago
Replaced Fan Relay (it was crispy inside the female section)
Compresser never comes on
Checked fuses
Checked fuse by battery

A few weeks ago I had turned off the car and the fan started up. When I turned the key back on, it shut off. I turned it off, fan on again. Started car and slid a/c on and truned car off. fan was now off. It did it again once more after that. It's been too cold to get the motor real hot lately so I haven't noticed if the fan came on or if the a/c was working. Now both don't work.

I am also confused about the "fan switch" I have read about. The one between 6 an 8. On the 305, one fan RS, do I have this or do I just have the one on the manifold by the thermostat.

Any ideas?

 

Arrggghhh! Fan switch!!!... Mine is stuck in my cylinder head and it leaks!

Your car does have a fan switch if its a FI 305 or 350 . The 350 is also has two fans w/ one controled by the computer (if aplicable). Its between the 6 and 8 spark plugs and it has a harness connected to it. The only thing i can think of now that could be causing your problem is possibly a dead power lead to your fan relay. Check the red (i thnk) wire for 12 volts. No power to the fan, no fan. As for the a/c, it doesnt work too well if you dont have a fan pulling air through the condenser to rid it of the heat it pulls from the interior.

 

I don't understand how the compressor not working and fan not coming on are related....

 

your problem w/ the a/c is probably unrelated but the compressor wont do too well if air isnt drawn through the condensor in front of the radiator. If heat, which is picked up by the R-12 refigerant as it expands in the evaproator, isnt removed, the system will get extremly hot and the compressor wont be able to liqufy the refrigerant.

I didnt see that your compressor never comes on in teh first post so the two are probably unrelated. My bad...

If you havnt replaced the fan switch, do it. Thats probably your problem right there... Dont forget to seal it w/ teflon tape or it will leak.

 

Looks like the compressor and fan work off of the same relay. I went to acdelco.com and noticed the same part for both. So now I'm thinking the piece that the relay fits into is the problem. It's pretty crispy where it plugs in. So now I need to find out how to replace that peice and if you even can without much hassle.

what would that be called?

 

well if you ever get stuck in a jam, you can just ground the switch wire going to the sensor on the block to the body and then jump the number one and three conectors where the bundle goes into the relay. the only problem with this is the fans will be on ALL THE TIME if the key is 'on' the wire go, 1, 2, 3, space, 4

 

It is called the relay connector. It is not uncommon to have a bad connector. You have two options, relace the female spades in the connector housing or replace the entire connector. In this area Pep Boys stocks a whole line of replacement connectors for almost any connector GM uses. It would probably easier to splice in a whole new connector. I would solder the wires as opposed to using crimp connectors, and then use heat shrink tubing to cever the splice. A short length of conduit over the spliced area and it will look like it was new. Danno

 

SS,

The cooling fan will not operate in AC mode unless the refrigerant high side pressure switch is closed. This will require the compressor to operate, and will also require some refirgerant in the system to make that pressure (at least 233 PSIG). Until you get some high-side pressure built in the AC system, the fan will not operate.

If the compressor will not run, it may be that the system has a low charge, or ambient temperature is too low to create adequate pressure on the low side of the AC system (at least 45 PSIG).