How to fix your broken heater fan cage ribs

Pramono · June 4, 2016

For those of you who attempt to fix your own heater box, I’m pretty sure you know what I’m going to be writing about.. A while back, I wrote an article about how I created a heater valve reinforcement bracket (you can see it by clicking this link). Since I’m still in this area of repair, I just wanted to give some ideas on how to repair the broken ribs on the heater fan cage.

This is what a fixed fan rib cage looks like.

The heater fan is mounted on the top section of the heater box with four clips. It is seated in a housing that we called the fan cage housing, since it looks like a cage. The cage consists of protective plastic ribs to prevent large debris entering the fan/ heater box, however, leaves and small debris are still able to go past these ribs. The factory did not make a screen or smaller openings to block the debris, thinking that airflow would be restricted. The ribs are made out of plastic, and as we all know, they become brittle from age and break, leaving even a larger opening (See picture below). Now there’s going to be even more debris entering the box! Nobody wants leaves and dirt blowing into their cabins, so I have found a way to fix these, that will make it look like the original again. I didn't like the idea of installing a screen, since it might restrict the airflow and is tricky to install. Besides, this way, it will make it look almost original again.

This is what the heater box looks like before being repaired. Imagine all the debris and leaves that have gotten through over the years!

Here is an inexpensive and simple way to fix it, and hope you may have some of these common tools. These what you need:

Materials required

• Coat hanger

• Epoxy/adhesive

• Paint/ Spray Paint

Tools required

• Cutter

• Pliers

• Marker pen

• Dremel Tool

• Burring bit

You will need to do this repair while the box is out of the car. Besides, I’m sure you wouldn’t want plastic bits flying into your box and core!

Step 1. Get a coat hanger and cut the straight part (this is what you will be using for this repair). Using either your hands or pliers, bend the section to match the curvature of the missing/ broken rib. Mark and cut the rod slightly longer than the length required (You will need to trim this later to the exact length). Cut and make as many as you need to replace the broken ribs. (See picture below)

Note: There are none of the shortest ribs where the fan motor mounting clips are located; they were left out on purpose to leave clearance for the clips.

Step 2. Get your dremel tool and attach the bit to cut/make an indentation on the vertical cross section on both sides where the ribs were connected once. Cut just deep enough so that the coat hanger will seat flush into the cut. (See picture)

Step3. Using your cutters, cut the rod to make it fit between the two cuts that you made earlier. (See picture)

Step 4. Place the new rib and align it so that it will line up both from top and side, and then apply epoxy to the end piece of the new ribs (see picture…).

Step 5. Sand, clean, and paint the new ribs (or the whole housing if you plan on doing a refurbish), and voila, you now have a new “unbroken” fan cage again! (See picture)