Condensation on instrument panel when running AC

[Hoppe]

When I run the ac in my new to me '84 the instrument panel gets cold and sometimes gets condensation. This is on the panel itself and not inside the gauges. This occurs on the right side and is coldest around the clock. Any ideas?

Thanks in advance.

Glenn

[McLaren-TAG]

You've probably got a hose on that side completely off the vent, that's feeding the cool air inside and not into the cabin.

[heimtun]

Following to see answers. I get fog on inside of gauges.

[kuehl]

As TAG pointed out....

When it happens again park the car on flat area, leave the AC on, open the front trunk and pull back the carpet away from windshield side inward. Inspect the primary ac air distribution tube; can become dislodged from the primary AC center vent above radio.

[DRACO A5OG]

+1 loose or leaking AC vent hose.

[wwest]

Might well be SOP, especially in Op's area, long periods of COLD airflow in an other wise HUMID environment.

With the A/C blower on Max you are likely recirculating the condensate that in a normal car would be discharged via the provided condensate drain. HIGH velocity air flowing UPWARD through the evaporator is more likely to "wick" condensate up and back into the cabin than otherwise.

Also "Bow-Tie" cool air outflow duct is right in the area of concern.

There is, of course, the possibility that you have a loose outflow fitting on the A/C plenum and you are inadvertently cooling the "frunk" area/volume. But given a closed lid on the smugglers box it might take a long drive for this to have your effect.

[Hoppe]

It's got a Kuehl vent over the bow- tie and it appears to flow well out of there. Air comes out of one half of the center vent but not the other. Based on the diagram above it looks like that is fed by the primary distribution tube so I don't know what could be happening there. I will need to wait until the weekend to remove the cover in the trunk to see if anything else appears to be loose.

Original owner was in Ohio and I am in NC. So humidity may be an issue. He put in a Kuehl evaporator and drier in 2012 and converted to R134a. The system was recharged in April 2014 and the car was parked for the winter, probably six months.

[kuehl]

We did a complete AC upgrade for a client's 930 in CT years back. One day he called me an said he was not getting cool air out of the center vent above the radio. I drove up to CT to see what was up. I turned on the AC and sure enough the air coming from the center vent above the radio was not the same as when it left our shop months back. So I opened the front trunk, pulled back the carpet from the panel behind dash, removed the black fiber board panel (4 screws) and took a look around. Lot's of 'stuff' behind the there, lol. So I got back in the cockpit and pondered what was up. I then looked at the center vent again and I noticed light coming through it? Sure enough the cowling connected to the primary air hose had moved away from the vent. Apparently the client had some work done (maybe wiper related) on the car after it left our facility and the technician inadvertently knocked the cowling off the vent. One mystery solved for the day.

PS. Its a good idea to have your front trunk carpets properly covering over that black fiber board panel and sealing up as much of the opening above it. You'd be amazed by how much outside air can get through the trunk and through your dash board.

[Hoppe]

Originally Posted by kuehl

As TAG pointed out....

When it happens again park the car on flat area, leave the AC on, open the front trunk and pull back the carpet away from windshield side inward. Inspect the primary ac air distribution tube; can become dislodged from the primary AC center vent above radio.

After much delay, I finally pulled off the panel in the trunk and could feel the cold air coming from on the drivers side. All hoses appeared to be solidly connected. I gave a slight tug to the main dash vent and it popped right out. The piece that connects to the primary distribution tube was only partially connected to the vent. Half the air was cooling the back of the instrument panel and the trunk. It was a pain in the butt to get reconnected but I now have much better air flow into the cabin.

Thanks for all the feedback.

Glenn

[kuehl]

No problem Glenn, glad to hear you are back down the right road.

[cabmandone]

Originally Posted by heimtun

Following to see answers. I get fog on inside of gauges.

Loads of threads on that problem. I'm about to remove a few gauges and fix the problem in my car.