Yeah, I might have exaggerated a bit about the heater. It works fine if I use it properly and give it a chance to warm up before I turn up the fan. The AC isn't all bad either. It gets the job done after a while and blows cool-ish but just takes a while to get cold if my car has been sitting in the sun on a hot summer day, which is to be expected I guess. It also works a lot faster with the car actually moving which is what they probably had in mind when they designed it, lol. I'm glad I don't have any refrigerant leaks I'm aware of. I have just seen better performance in other cars I've been in. I used to have an '01 Accord (same generation as your '99 I believe) with superior heating and cooling performance but unfortunately I got hit from behind a couple years ago so that car is history. My '97 is in an overall much better condition than that car was while I had it so I am grateful for that.

 

You may want to lightly spray the condenser with a hose to clean off any dust/debris. Don't hit it full blast with your garden hose, or you will bend the fins and prevent air flow.

Also, when you start your car and turn on the a/c, do both fans on the radiator turn on?

 

That is a good idea and something I will try. I had a new condenser installed about 4 months ago along with my other AC components (compressor, receiver/drier, expansion valve, evaporator) and it still looks in good shape. A few bent fins but some of them were that way before I even installed it. I'm sure lightly spraying it with water wouldn't hurt it. I have a few leaves stuck between the condenser and the radiator so it will be a pain to get those out and perhaps those could be affecting the air flow.

Yes, both front fans come on when I switch on the AC and whenever the compressor clutch engages. In fact, the fans will come on periodically when I have the temperature set on cold with no AC given that the engine is at operating temperature. Interestingly, they rarely ever come on when I have the heat turned up (without AC) because I think the blower fan in the cabin is cooling the coolant flowing through the heater core so the front fans at the radiator aren't needed as much. So I guess the fact that the front fans come on more with the dial set to cold could mean that the heater control valve is working at least somewhat properly by cutting off coolant flow to the heater core and forcing all the heat dissipation of the coolant to happen at the radiator. I should also mention that I put new 50/50 antifreeze/water mix in just over a year ago and there are no leaks with that I'm aware of in the cooling system. The temperature gauge is also in normal range. It always stays below the halfway mark which I saw is normal for Accords in that generation with the thermostats they use.

 

Increased resistance in the middle of it's travel … maybe you do want to get a helper to watch the valve. Maybe the cable is kinked or something? If anything looks suspicious as it moves, that might be a hint for why it doesn't close all the way?? The cable is much more effective at pulling, not so much at pushing on the valve lever. I don't remember which way is cold, pushing or pulling the cable.

 

Yeah, that's possible. I didn't think about that. I will have to see if the cable and valve arm are moving steadily without any sudden jolts or if the cable gets kinked at some point. I know from earlier observation that turning the dial from cold to hot will push the cable that goes from the dial to the blend door and somehow that in turn causes the cable that goes out to the valve to pull the valve arm back towards the firewall. The opposite happens when going from hot to cold on the dial. I attached a photo of the area where the two cables connect under the dashboard that I had taken earlier with the dial in the full hot position. Unfortunately I didn't get a very good shot of the cable going out to the valve as it is partially obscured by the carpet. I can take a better photo once I get back. I will say I was able to watch the cables in that area when I turned the dial and didn't notice any kinks in the cable going from the dial to the blend door arm. I wasn't paying close enough attention to the cable going out to the valve to be sure that there were no kinks but that will be something I check once I get back.

 

If you get stumped, it looks like you can disconnect the cables from this bellcrank, and separately push each cable back & forth to see which part is sticking or whatever. Also push the bellcrank back & forth to feel the air-blend door moving. Maybe its something simple like the carpet getting in the way?

 

Yes. I suppose I could at least see if the two points on the bellcrank where the cables connect go any further if I push them by hand with the cables disconnected. If they go further than what the connected cables allow then I suspect the cable housing could have slipped in its clamp and there might be a sticking point in the cable's travel. Otherwise it would lead me to believe that the cables are aligned properly at least on that side. I still couldn't rule out the possibility of a slippage on the end of the cable housing by the heater control valve until I make sure the valve arm moves no further with the cable disconnected than with the cable connected. If that all checks out then the valve itself might be defective or the temperature difference is simply due to a mix of hotter engine bay air and ambient air getting pulled in from the intake vent at the bottom of the windshield. I actually experimented with this idea a few weeks ago with the blower fan on high. I found that if I let it run this way with the hood up, the air coming out of the vents actually gets warmer, creating an even larger temperature difference between the ambient air and the air coming out of the vents than when the hood is down as usual. This leads me to believe that the hotter engine bay air has at least some influence on the output temperature. I just don't know if that's the sole influence or if there are other factors at play.

 

That makes sense when the hood is open. There's a kind of rubber weatherstripping in front of the cowling, preventing hot air from coming directly into the ventilation intake. Is that intact? With the hood closed, especially when you're actually driving, the hot air mostly comes through the radiator then goes down to the ground.

As far as a bad water valve, I guess the only way to really be sure is disconnect the hoses & look inside as you push the lever back & forth. Leave that for the end since you'll have to drain a bunch of antifreeze.

 

I think I see the rubber strip you are referring to and it looks to be intact. After paying closer attention I have noticed the air from the inside vents gets cooler when the car is moving so I think you're right about the engine heat being displaced by cooler outside air while driving. When the car is stationary there is very little air movement in the engine bay so the heat is allowed to rise and some of it gets pulled into the intake vent. The rubber strip must help alleviate some of that but it's not a perfect seal, at least in my case. The holes on the front side of the intake almost make me think it was purposely designed to pull some amount of engine heat in through the gap between the hood and the rubber strip while pulling ambient air in through the top side of it. I've been in cars where the fresh air intake isn't situated under the hood, but instead more exposed to the outside air right in front of the windshield, and the air temperature coming out of the inside vents is very close to the outside temperature. So on mild days, one could get away with using fresh air ventilation without A/C or opening the windows. Sadly this doesn't seem to be the case on my Accord and I don't know whether I can do anything about it or not. There is always the possibility that the water valve isn't closing all the way like we talked about earlier but I haven't got to testing it yet. I wish the thing wasn't buried under the intake hose because I would have tested its movement a long time ago otherwise. I'd rather get someone who knows what they're doing to take the hose off and put it back on when I'm done but maybe I can find a useful how-to online about how to do it and get around to it when I have a good chunk of time and the right tools. Anyways, I attached a photo I took of the intake vent by the windshield with the rubber weather strip in front of it. Hopefully that can shed some light on things. Thanks again for the responses. I truly do appreciate the input.

 

I don't believe any air comes from the engine compartment "by design". Too much chance for oil vapors, exhaust leaks, or stuff like that to get into the ventilation system (and car company lawyers don't like those kind of liabilities). It looks like that weatherstrip is OK and you can see the clean-ish strip on the underside of the hood where it closes against the strip. It doesn't look like your hood is bowed upwards from collision damage or anything silly like that.

I think the inlet screen is pointed that way to avoid getting rainwater into the cowling, not to get any hot oily air from the engine compartment. But you might want to look all over the firewall for openings. Things like wiring harnesses feeding into there need to have grommets or caulking or something like that to make them mostly sealed. And that rubber-stuff is 22 years old...