Are you one of the many SJ owners that drives around in the winter months freezing because your SJ heater does not work properly ? Well, here is an easy solution to the problem.

The SJ heater airbox seems to attract leaves and other debris. This debris lies on top of the heater core limiting the airflow, with the result that the heater is not as effective as it should be. The answer is to clear out the accumulated leaves and dirt. Here is an easy way that will allow you to clean out the leaves without dismantling the entire heater unit.


Tools and equipment ...

-½" Masking tape
-Vacuumn cleaner with a small diameter hose of about 1.5" or less.
-Drill
-Hole saw slightly larger than the vacuumn hose.
-Something to use to plug the hole afterwards.
-Silicone sealer
The total time for the job should be about ½ hour.

Cleaning the Heater unit ...

Pull out the flexible hose from the side of the heater airbox and tuck it up out of the way. Now, using the masking tape, mark out a line from the curve at the rear of the heater airbox to the step in the front. This is the approximate highest point of the heater core. All drilling MUST take place above this line. If you drill below this line, there is a very good chance that you will drill through the heater core and it will then need to be replaced.

Once you have decided where to drill, check the area again to make sure that you are not going to drill into the heater core. The to be absolutely sure, check again. It WILL be an expensive mistake. Now carefully drill a hole through the plastic casing using the holesaw. As an alternative, you could drill the hole in the front of the airbox instead if you don't have enough room for you drill under the dash. The end result will be the same.

Here you can see where the drilled hole is located in relation to the moulded area on the plastic heater housing. If you look through the hole, you should be able to see the leaves and other debris that has collected over the years lying on top of the heater core, thus blocking the airflow.

Using the smallest attachment of the vacuumn cleaner, suck all the unwanted debris off the heater core. Be very careful not to damage the surface of the core, as it can be damaged by rubbing, just like a radiator.

The finished project ...

Once you have sucked all the debris off the heater core, you need to seal the hole. To seal the hole a rubber grommet, a plastic plug, or a toggle bolt and washers can be used. If using any of these methods, it is advisable to apply a small amount of silicone sealer to the surface edges of the hole before sealing. This will create a better seal and stop air leaking out. The hole can even be sealed with black duct tape.

That's all there is to it. With just a few simple tools and half an hours labour, an efficient heater. Finally, cold winter days are a thing of the past.