Tough smell to kill, the air enters through the top of the cowl and flows into the heater box. Your problem is probably that all the mouse waste is accumulated down the sides of the cowl where it is supposed to drain into the rockers. I bet you'll find that those areas (especially the passenger side closer to the heater) is blocked with a mixture of leaves, muck and mouse stuff.
Good test is to pass a garden hose down the cowl towards one rocker and open her up (make sure your kick panel vents are closed). Water should pour out the various holes in the rocker (assuming there are no rust holes the drain is on the inside of the rocker panel-facing the frame-just before the rear wheel tub. Try sticking your finger in that hole and see how its blocked up, or stick the hose in there to loosen things up.
If its blocked really bad you might want to pass a shop vac hose down the cowl to suck up things. The hole from the cowl to the rocker is pretty small, they blocked easily.
Once you get both sides flowing clean water I'd saturate the cowl with spray-nine and let it sit in the sun for a few hours to kill remaining bacteria before rinsing it out.
Here's a photo of the bare firewall of my 70 Parisienne. Your car 67 would be the same.
The air enters the cowl area, and goes down the sides of the firewall towards the rocker panels. The heater fan sits in the round hole in the left of the photo, and pushes towards the square hole where the heater core sits. Different flappers direct air either through the heater core or past it, and also to floor vents or defrost vents.
Your mouse may have made a mess anywhere in there.
The heater housing that sits in inside the car is fairly difficult to remove, as it's installed before the front fenders & inner fenders are installed. For 67's, I believe if you remove the inner fender, then you can access all the nuts to remove the heater housing, and the fan etc.
Did you solve your smelly heater problem.
I have a heater box non a-c that has sat on my bench too long.
Will need a clean up/restore
where do you live
let me know and I can send photos if interested.
just been reading old posts....interesting.....
Yes
I did exactly what North recommended!
Found a huge nest in passenger kick panel!
Shop vaced it up , washed it out with garden hose
Stink went away shortly after that!
Not long after that heater core went!
So I painted and cleaned everything when it was apart
All good now!
Thanks for your interest.
Greg
