TCvette98

A/C blowing cold air out drivers side only on 1998 C5

SG Lou

Have the Freon checked. Low pressure usually causes the symptoms you are describing. Another problem could be be the passenger side Blend Door Actuator.

Volk2142

. I had the same problem, but driver side hot passenger side cold. Then the ac compressor clutch burnt up.. so now I don't have ac, ripping it out this weekend because racecar

Rob 02

Blend door actuator. It's a fairly common problem.

With low refrigerant you cannot make cold air at all.

Check codes! That should tell you.

GCG

As mentioned above, that's usually a sign of low refrigerant.

Take a look at this post. It has detailed instructions to check/add refrigerant and a chart that might be helpful to you.

TCvette98

Checked for any codes; there were none! A/C compressor was changed out last August. This did happen once before and was able to fix by pulling fuse #27 and re-installing. This time pulling the fuse doesn't seem to be doing the trick.

Rob 02

Does a 98 have dual climate control?
Sorry, I'm mostly familiar with my '02 and don't want to make assumptions.

TCvette98

Yes, it does have dual climate control. The display is getting hard to read; gets faint after a few seconds (probably needs to be replaced).

Rob 02

As for the display, there are 8 resistors on the back of the circuit board that need to be re-soldered. I had to do mine. The unit has been out of production for some time.

I will dig up a link to a thread on this when I get a chance if someone doesn't beat me to it. I will also look up your HVAC problem in my factory service manual in the morning to confirm or debunk my suspicion.

pewter99

if you decide its the actuator I have a new one (used 90 days) for sale $30 shipped...good luck..AC issues are a pain in the ***

TCvette98

Thanks, appreciate all the help. If it is the actuator, is there a thread that describes, or better shows, how to remove the dashboard? I was able to find a thread that had a link, but I guess it was old and it was removed.

laurent_zo6

This might help:

Rob 02

Here is a good thread for the HVAC dual climate control repair.
https://www.corvetteforum.com/forums...splay-fix.html

Rob 02

First of all I have A/C tools (gauges, thermometers, vacuum pump etc..) and I'm not sure what tools you have at your disposal for troubleshooting. The thing is, before doing a proper diagnosis you need to know that the system is charged with refrigerant, that the compressor is working properly that the orifice isn't clogged and that there is no air or moisture in the system. You use gauges to get this information.

Assuming the above is all working properly I would check for codes which you have already done.

I use a meat thermometer placed in the vents to note the temperature(s).

With all the above checking good you have pretty much narrowed any problems down to electrical components and controls in the dash.

I would hate to see you go through the trouble of removing the dash unless you are sure the rest of the system is functioning properly. If you want to assume based on faith or knowing your cars history that everything under the hood is good then that is up to you. Risk vs reward.

With all else checking good I would then consider the blend door actuator as the culprit.
If you do replace one actuator then I would replace both since the life expectancy is about the same and you probably don't want to do this again any time soon.

If you go into the dash I would consider any other repair,maintenance or up-grades you want to do that would require disassembly of these interior pieces.

GCG

As I mentioned in my previous post, there is a good chance the system is low on refrigerant. It could be a blend door actuator, but it's easier to check the refrigerant level first than to tear down the dash

I linked a step-by-step guide with a chart for the pressures vs ambient temperature and humidity.

NOTE: I kept thinking on this and did some searches to double check. The low refrigerant symptom would be the opposite of what the OP is experiencing: cold in the passenger's side and warm in the driver's. Nevertheless, I would check the pressures first before dismantling the dash

TCvette98

Checked AC system and got readings of 35 on the low side but no reading on the high side at approximately 2000 rpm.

GCG

Something is not right here. If it blows cold air at least on just one side, the compressor has to be doing something and pressure on the high side should be higher than on the low side.

Are the gauges in good condition? Are you sure the high side connector is depressing the valve?

Rob 02

That's low and I doubt it was enough for the compressor clutch to have been engaged. How were you getting cold air out of either vent? Was it just the fan blowing?
That's why you use a meat thermometer.

Were the high and low sides equal with the engine off?
The reason I asked is because it is odd to not have a reading on the high side.
Are you sure you don't have those figures reversed (35 on the high and 0 on the low)? This would make more since. If so then you are probably just low on refrigerant.

TCvette98

Thanks for help. Just checked again and got 27 on the low side and 275 on the high side with the engine @ 2000 rpm's. The ambient temperature is about 100 degrees.

GCG

To accurately use the chart in the message I linked above you also need the Relative Humidity.

For example, if the Ambient Temperature is 100°F @ 60% Relative Humidity with:

• Engine @ 2000 rpm
• A/C in coldest setting
• Fan at maximum speed
• Both windows down
• Thermometer in center air vent

You should get:

• Low side 43
• High side 360
• Center Duct Air Temp 73°F

If your readings were taken under these conditions, then you are a little low on refrigerant.

When adding refrigerant, pay attention to both pressures, otherwise you might end up with the high side sky-high trying to get the low side to the chart's value.

Let us know how it goes.