I hope I have successfully and finally served the eviction notice. I don’t wish to be heartless, but it came down to she or me. In this post, I am going to describe how I went about it. If some of you have the same trouble, maybe my experience will help you.
Before I waste the time of any budding landlords, let me confess that my tenant was a little gray mouse that had taken up residence as a squatter in the heater of my 1996 Toyota Rav-4. I saw her scurry across my garage only once, but she is one very industrious rodent. I have spent two full afternoons in the last month working at reclaiming the function of my heater. A working heater is essential in Winter in Iowa, if only for the defroster.
Apparently, there are no mice in Japan, or the Toyota design engineering team would have known to exclude my mouse from the mechanism. As having to do this job twice shows, they also didn’t make it easy to permanently resolve the problem. On the first attempt, I cleaned out the nest packed into the blower and heater core enclosure. This work took about three hours of standing on my head, under the dash. Once the blower ran smoothly, instead of like a washing machine spinning with a basket ball, I set about prevention.
Removing the blower assembly isn’t too hard. First, remove the glove box. This task is accomplished by opening the box and squeezing the sides in to get the back stops past their blocks. Then tilt forward to expose and remove two screws. Don’t take the screws out of the hinges, but the two at the end of the bar the hinges are attached to. The bar fits over a couple of plastic guide pins to make reassembly easier.
With the glove box out of the way, the blower assembly is removed with just three screws. I used a flat head screw driver. Something about those screws didn’t quite match my #2 Phillips. You will probably have to flex the corner of the plastic dash to get the blower past it. Squeeze the catch on blower wiring harness to unplug it. Having the blower completely out of the way will aid in cleaning, etc.
I wanted to remove the lower half of the plastic housing that goes around the heater core. However, there are screws in the back – way up behind the heater core assembly. I could see them with my mirror, but staring at them fiercely didn’t make them come out. It’s probably just as well. It would have been even harder to wish them back in. I can only assume the proper disassembly procedure starts with “remove dash”. Removing the dash definitely would have exceeded the time I had to devote to the task. Instead, I cleaned out the intake side of the heater core though the hole left by removing the blower motor ballast resistor assembly. This resistor is inserted into the airflow for cooling. Removing it left a hole just large enough to insert the narrow crevice tool for my shop vacuum. Some careful fishing with a hooked piece of coat hanger wire mostly did the trick. A pen light will help you see into the hole while you fish. There are some cables or tubing on the intake side of the heater core, so be a little careful.
I had hoped to access the heater’s outside-air intake port by removing the plastic grille at the base of the windshield. I removed the windshield wiper assemblies and then the grille. I found, unfortunately, that the port going into the heater is not accessible. (One can see it with a flashlight, but it is at the end of a long sheet metal tunnel on the firewall.) You unthinking vehicle designers take note: applying a screen over that intake would have been easy before the firewall was all welded up. I decided to screen the four topside holes underneath the grille, on the possibility the rodent was making ingress around the over-sized holes for the wiper shafts. So, I’m telling you now; that exercise is a waste of time. Water has to drain from that channel somewhere. The hole must be at least large enough for a cold mouse.
Tearing into the heater was enough work that I admit to a sense of dismay when the unbalanced blower recurred. Only a couple of weeks had passed, and I still had sore knees from kneeling beside the passenger door all afternoon to access the heater. As I repeated the under-dash headstand today, I was a little faster and smart enough to dig out some knee pads. The nesting material was different, but just as problematic for the heater. As I redoubled my efforts to find a way to prevent recurrence, I noted the damper to select inside or outside air closes pretty tightly. Henceforth, I resolve not to park unless I return the damper to the inside-air setting. However, that opens the intake to the interior. I have seen evidence that mice can get into almost any car interior. To address that problem, I screened the cabin intake on the heater assembly. Compared to the outside intake, the cabin intake is (almost) easily accessible. The screen I used is 1/4” hardware cloth. Screen with larger holes won’t keep the mice out. I attached it by passing U-shaped pieces of galvanized steel wire around the plastic lattice that forms the face of the intake (from inside the blower housing). I held the apex of the U tight to the lattice and bent the wire over the screen. Nylon tie wraps would be easier, but I wanted to make sure it was gnaw proof. You may notice from the picture that I used a couple of small cable ties to hold the screen in place so that I could use both hands to work with the wire.
Make sure the wire is not protruding on the inside, as the damper needs to be free to close off this intake completely. Once you are satisfied with the screen, reinstall the blower and the glove box.
Of course, only time will tell if I have been successful at enforcing the eviction.