PaulW

My A/C works fine on my '94 Civic Vx in cool weather, but when it's hot outside it won't turn on. What I mean is that in cool weather, I can feel the A/C clutch engage, with the RPMs increasing a little and it blows cold. But when it's hot (+75 degrees), the clutch never engages. The vent blower works, just no cold air. Previous owner recently installed new freon and o-rings.

Any ideas?

Paul W.

honda.lioness

Take the Climate Control Unit out of the dash and check the A/C switch and also its associated soldered joints on the CCU circuit board for the required electrical continuity. I think the joints may expand when it is hot and so fail to maintain electrical continuity. This is just like the notorious main relay's soldered joints on older Hondas. I resoldered my CCU's a/c switch joints on my 93 Civic last summer and am waiting for really hot weather to see if this fixed it. Writeup: http://honda.lioness.googlepages.com/airconditioning . One of the symptoms was it would work fine first thing in the late morning when I took it out of the garage for a drive, but then after driving a while in the heat, it would not work. Others with similar symptoms have said they took their Civic to the dealer who then diagnosed a bad a/c switch and so in dealer terms a bad CCU.

Former User

Purchase or borrow a set of A/C manifold gauges to test whether the system is overfilled with refrigerant.

PaulW

It looks like it is bad soldered joints on the AC/Heater board.

I've been leaving my windows rolled down while parked at work on hot days. When I come out to the car, the AC works just fine. But when I leave the windows rolled up, with a black car, the cabin temperature gets pretty high and the AC never works.

So my quick fix is leaving the windows rolled down, which is OK for now, cause we have a gated security parking lot. In the long run, I'm going to have to figure out how to pull the aftermarket radio and AC controls to resolder the joints. Some fun.

Thanks for the help.

PaulW

Yea! My A/C is fixed. The problem was a bad climate control unit. (probably bad solder joints).

I bought a refurbished unit from an ebay seller with a two year guaranty. He also changed the LEDs to blue to match my Sony radio. It took me five minutes to remove the radio and ashtray console....and an hour to undo the two climate control wire harness connectors. Throw in a couple of bloodied knuckles and I now have a big cool smile on my face in the hot weather.

paulw
94 civic vx

wahidstx

I'm in a similar situation. I'm glad to see the posts here including the picture. Thank you, thank you, thank you. I'll investigate my AC control unit.