My problems started with the classic warm air on the driver side and cold air on the pax side. I also noticed the fans cycling. Ok its low on freon I suspected and added some. This seemed to fix the problem until the next time I drove the car and the scenario was back.
Now fast forward to the Eureka Springs Corvette weekend. The wife and I had been downtown for lunch and when we left for the hotel we stopped at a stop sign and the car just died. It started back up and we went on to the hotel. The problem became worse until it would not start at all. Out of desperation I went to the fuse box by the battery under the hood and checked the fuel pump fuse and swapped the horn relay for the fuel pump relay. I turned the key on, heard the fuel pump run and the car started and was normal the rest of the weekend. After getting home I decided to change the driver side actuator for the hvac and see if that would fix the warm air on the driver side. It did not. But I did notice the fan was cycling and when it was running the driver side air would be cold like the passenger side but when the fan turned off the air would warm back up. I went to the same fuse box under the hood and pulled all 3 of the relays for the fans and re-racked them as I like to say. After doing that the fans run on low the whole time the air was on and the driver side air is as cold as the passenger side.
Looking at the terminals of the relays did not really show any signs of corrosion but I know all I did was re-rack these relays and everything went back to normal. I went ahead and pulled every fuse and relay in that box and used some contact cleaner to clean the terminals and re-installed. I also cleaned the grounds to the frame right there below the battery.
I have read a lot of posts on this very problem and would recommend what I have done to see if that will fix your C5 havac problems.
By the way our car is a 2000 vert with 39,xxx miles.

 

So your saying:
Clean the fuses in your fuse box
Re-rack the relays (Could you clarify on this?)
And clean the frame ground underneath the battery?

 

Unfortunately, our C5 connections SUCK. They frequently loose tension and fail to make properer electrical contact between the male and female pin s. The female pins spread and loose grip on the male pins,,, be it fuses, relays or connectors. When ever you have an electrical issue,, make sure that any thing with a male and female connection has a nice firm positive grip. You MUST feel force inserting and retracting the male pin..

I have various MALE pins that I use to test the female pins

WSS Connector GOOD and BAD



MALE TEST PIN

 

That is what the bad pin on my DLC (OBD2) port looks like.

You can find pins, but the crimper is likely a special tool.

Ever replace pins Bill? A lot of these connectors aren't really made to be taken apart. The service manual does however refer to replacing pins.

As far as re-racking, well, I believe that just means removing, then putting back in. If there were a smidge of corrosion, removing and re-seating will clean the contacts for you.

Ron

 

What I am saying is my experience recently tells me that the relays and the fuses in the fuse box at the battery should be pulled, I suggest one at a time, take some contact cleaner, LPS makes a good contact cleaner but you can also find contact cleaner at radio shack, spray it into the receptacle for the component you have pulled and also on the spades of the component. Then take some dry air and blow it dry. I also suggest using a di-electric to kote the spades before re-inserting the component back into it's slot. Then move onto the next component. But before you do any of this work I recommend to disconnect the battery. When I did this I found that the few electrical gremlins I was having went away. I hope this clarifies the re-racking term I was using for pulling the component and plugging it back into the slot.

 

Ron

There are aftermarket companies that make pins and pin tools for GM Delphi weather tight connectors.

Some connectors are molded and the pins can not be replaced. That requires purchasing a pig tail splice in replacement connector.

I will talk to someone that I know who has one of those pin repair kits and get the data.

Bill