Hello... This is a weird one. My '89 Bronco II fogs up on the interior of the windows, so bad to the point of needing a small scraper in -20 weather. I've already replaced the heater core. Some things I am thinking are perhaps the fan is shot and just not blowing enough, or the door seals. Am I right? Am I way off? Any help would be super.

1989 Bronco II Eddie Bauer w/ A/C & 2.9 L V-6

 

If your heater core is leaking that will cause the fogging. Do you have a funky sweet smell when you get the foggging? Are you having to add water/antifreeze to the radiator? If not check the vacum lines that go to the back right of the engine as you face it. They(about 4 lines) come of the upper intake manifold. The small one pointing down controls the air door that opens & closes the door that contols the air mixture.Hope this helps.

89 Bronco II XLT
92 F150 ext cab XLT
93 Aerostar AWD

 

Well... I checked the vaccuum lines... Everything seems to be in place.. Nothing appears to be melted or wrecked. The heater core is fine as well.

Perhaps a few more tidbits of info will be of help...

I can start the truck and leave it with the heater on and there will be no fog. As soon as people get in, even just one, it fogs up. The people get back out, it de-fogs... strange... any ideas?

Mike

'89 Bronco II

 

Do you have aircondition? When the heater cuts on the aircondition cuts on to dehumidify the air coming in. If that is not working that could be your problem.Also is the door for the outside air opening & closing?