Good Afternoon All!!
I have a dillemma in the old '71. Every time that you turn on the defoggers, or heat, it steams the windows so badly that you can't even see...(even without beer...)
I would really appreciate any ideas to cure this unatural phenomenon!!

Thanks, and my best to you all,
GRIZZ

Sounds like a heater core to me,or maybe just a bad clamp at one of the heater hoses inside the car.No coolant leaking inside the car on the floor??

heater core is leaking. after repairing, the inside of all windows will have to be thoroughly cleaned

get that fixed ASAP or you will be replacing carpets too!!!

Sounds like a pin hole in the heater core. If you don't want to pull the core, you can put a can of radiator stop leak in the radiator and it will plug the hole in the heater ( turn on the heater of course to get water flow through it ) and yes, I know a bunch of people will right quick say that it is not a good fix but it does work. It you don't want the 'stop leak' in your system, put it in and run the car till the leak stops and then back flush the system to get out the stop leak still floating around in the water.

Before I put stop leak in my cooling system if I didnt want to replace the heater core I would bypass it.

Thank You all very much!! After careful examination, your assumptions are correct....Heater core leak...As suggested, I bypassed it untill a decision can be made...THANKS ALL!!

The GRIZZ