I am in the middle of a complete rebuild of my 1996 Impala SS. Once done, it will not be a daily driver and may sit for extended lengths of time - especially during winter. I've read horror stories of people finding mice nests in their heater boxes. Usually the little critters like to build their homes in the fan since it is the perfect size easy to get to. I didn't want to worry about them so I devised a plan.

I actually have had the entire dash out but I am sure this can be done with leaving most of it intact. There are quite a few items to remove but for me, it is well worth the pain now than dealing with it later.

Both windshield wipers and cowls will need to be removed to gain access to the air inlet to the heater box. There is 1 nut on the stud poking through the firewall just below the inlet that will need to be removed as well as the 3(?) screws you access from the engine side. The top of the dash will also need to be removed so you can gain access to the 3 10mm nuts holding the top of the assembly. With everything loosened you should be able to pull the heater box ¼ inch away from the firewall creating a gap between the air inlet heater box boot and the firewall. It should look like the picture below.

http://i482.photobucket.com/albums/rr187/carbqss/Rodent%20Screen/02HeaterBoxMoved.jpg

Next cut a piece of fencing about ~ ¾ inch larger than the opening. I had some laying around so I didn’t have to buy anything but it should not cost you more than $10 bucks at your local hardware store.

http://i482.photobucket.com/albums/rr187/carbqss/Rodent%20Screen/03ChickenWireCut.jpg

From the inside of the car, slide the screen mesh between the firewall and the heater box. Once satisfied of its placement, start reassembling everything you removed. When the heater box is once again tightened in place, it will hold the screen from moving. You now will have a rodent free heater box for 10 bucks!

http://i482.photobucket.com/albums/rr187/carbqss/Rodent%20Screen/05WireMeshInstalled.jpg

Hope this helps somebody. Good luck and let me know how it goes.

How did you get the wipers off?
Would the filter mod prevent mice or do you think they'd chew thru it?
I have mine open right now for parts sent off to paint, It's not a DD as well, but doin somethin here now is on my mind...

I had to ask since I'd never been able to get mine off either. You carerfully remove the plastic bolt cover by prying on the sides. Next pull off the nut. With some force, wiggle/pry the windshield wiper off the tapered splines. You then can remove all of the screws that hold down the two cowl plastic pieces. You now will have access to the area you need to get at.

Unless there is something metal to keep the rodent out, they could easily chew thier way into there. Depending on the filter, a mouse could use the filter media to build the nest :(

How did you get the wipers off?



1. Remove wiper arm pivot nut cover.
2. Remove pivot nut (13mm I believe)
3. Lift wiper arm from windshield.
4. Locate small hole in wiper arm, just above hinge point.
5. Insert small screwdriver into hole, ensuring it also goes through the hole on the opposite side of the arm. This will relieve spring tension off of the pivot point.
6. Remove wiper arm from pivot shaft. It will come off with little or no effort.

Unless there is something metal to keep the rodent out, they could easily chew thier way into there. Depending on the filter, a mouse could use the filter media to build the nest :(

Ya that would definatly backfire.
Maybe there is a way to combine the 2 methods.

Thanks for the wiper removal process, I'm gunna have to try that.

I removed my cowls with having to do it, but when there painted I don't want to wreck the paint sliding them back on.

Very useful info!

A cheap and easy temporary fix for rodents is the placement of laundry dryer (Bounce or similar) sheets under the dash, under seats, in trunk, etc. For longer storage, insert in exhaust pipes, under hood, etc.

A cheap and easy temporary fix for rodents is the placement of laundry dryer (Bounce or similar) sheets under the dash, under seats, in trunk, etc. For longer storage, insert in exhaust pipes, under hood, etc.

I heard about that, my buddy does that to his cabin in the winter. He refreshes it every other week when he's up there for snowmobiling.