I like heat too much to do that!
A coolant leak is causing the problem, find it and fix it, heater core as suggested previously is a prime suspect.
You need to replace the heater core ASAP. Breathing anti-freeze is not at all good for you.
The heater core is essentially a small radiator. The hot coolant flowing through the heater core is used to warm air entering the cabin. Your heater core has sprung a leak and coolant is vaporizing and those vapors coat the inside of your windshield and they are not at all easy to clean off.
Replacing a heater core is fairly hard to almost impossible depending on the make and model of the car. Some cars require extensive work to remove most of the dashboard just to access the heater core area. I’m not sure about the '97 Odyssey, but figure about $500 for this one and it maybe a bunch more.
taking my car to the shop this morning, thanks!
Is there any chance you have the air set to recirculate rather than fresh air? Don’t turn on recirculate until it has warmed up. It also may help to leave the electric defoggers off until you get the front windows clear. However I don’t believe you should be driving while any window is fogged.
I’m with the heater core crowd on this one
If your heater core is leaking you can usually smell antifreeze. Do try cleaning the inside of the windshield, though. Windshields tend to accumulate a film of crud on the inside and it can really hold onto the fog.
Go over it twice with Windex and wadded-up newspaper. It’s amazing what that’ll do!
If your odyssey has an cabin air filter it might be plugged, I’m seeing a lot of cars with the cabin air filters with that same problem. Once the filter is plugged you can’t draw enough outside air into the cab so the wet air inside the cab just get re-circulated.
I see a lot of Fords with the problem as their filter filters outside air, my Buick’s filter is inside the cab and I don’t get that problems.
My opinions are subject to change with new facts.
If it’s the heater core, the amount of fog will be ridiculous – much, much more than on your side windows. That’s the giveaway clue.
You might also notice a sweet odor from the antifreeze. Some people say it smells like maple syrup. None of these people are from Vermont.
That all depends on the size of the leak. The last heater core leak that I had was very small and did very little fogging.
I, too, own a 1997 Honda Odyssey with 152K on it. I’ve owned it for twelve years. Here are some tips I learned long ago… first you have to push the A/C button “on” with the fan set for defrost, then adjust the heat/cold level to a bit warmer if the weather is cold (that’s a ‘no brainer’). That also takes care of the moisture which is the culprit. You also can direct more air to the windshield by closing the two door side vents. (Roll the thumb wheels on both sides closed.) NEVER try to defrost while using the “recirculate” button or the"fog" instantly comes up. Hopefully you got your answer at the shop already or heater core replaced if that WAS the cause in your case…the fogging has been a source of annoyance for me since I bought the car. I love it and will keep it anyway. The braking system rated 5 stars, and I have had several occasions to check it out! They are dinosaurs and I will keep her till she dies…GREAT VANS with four doors…