skullz92!

hey guys I have a question that I need help with.
when I turn my defroster on I get a funny smell and my windshield tebds to fog up. im not sure what could be causing the problem. I have read similar posts on here and allot of people tend to say heater core needs replacing. Is there anything I can do to diagnose the problem myself.

88 orangepeel notch

You already diagnosed it correctly. Fogged up windshield and a sweet smell of heater core failure. I've heard it's quite a chore to replace, but mjr has a trick to doing these without pulling the dash. If you ask nicely, he may share........

Welcome to the forum by the way.

mjr46

pull the dash and replace the heater core

skullz92!

thanks guys.. I appreciate this. I have never done a heater core and if this MJR. person is willing to share a secret I would gladly appreciate it. if not I understand. also I went home and turned the defroster on again and it did not fog up. it only seems to do it when there is moisture in the air. this is my first fox body and my second mustang. although the first mustang I had was a Frankenstein and had a mixture of different years on model parts holding it together.

mjr46

no secret on a 87-93.....if the car has or had a/c........you have to pull the dash out/back enough to gain access to the heater box which has to be pulled away from the firewall to remove the heater core cover

skullz92!

gotcha.. I see what you are saying. now does that mean I am going to drain antifreeze and stuff. if so where are the easiest spots to drain the heater lines. or is it pretty much unclamp hoses to heater core and let it drain itself. I am gonna replace all radiator hoses as well. any other tips or advice guys again I appreciate it.

88 orangepeel notch

There is a drain valve at the bottom of the radiator, on the engine side. That will drain everything.

sofknez

There is a drain plug on the bottom of radiator unscrew and open cap to let air in for better flow

mjr46

why waste time draining the radiator, get 2 hose clamp plier or two needle nose pliers and pinch off the lines or loop them together if you have a radiator flush kit tee

89redgt

Had the same issues last year on mine it is a full days work but its defently your problem. Dont worry about the coolant to much but make sure you have some rags on hand and keep track of all the screws as you pull the dash apart. There are alot of good videos on youtube on how to do this step by step