Before you start tearing the dash apart, there are a few easier things to check. I too hate tearing a dash apart. They almost always vibrate after you do it no matter how careful you are in putting it back on.
- This may seem ironic, but check your engine coolant and make sure it's not low. The heater core is actually tied to your cooling system as it uses the same liquid. If you are low on coolant, it can screw up the interior heating.
- Replace the thermostat. Again, interior heat is tied to the engine cooling system. It's very easy to replace but you will need to drain some coolant from your system. Remember to capture coolant cleanly when you drain it. It can kill your dog or cat and for some reason, they say they are drawn to its smell. The thermostat is behind the lower radiator hose. Follow it down to the water pump and remove the hose and it's right there behind it. Like most items, it's very easy to get at on a Jeep.
-- There could be a blockage somewhere in the cooling system to your heater core. If you suspect this, you can back flush the system.
-- The heater core could be toast. The bad news is, to remove it, you still have to remove the dash. You can find detailed instructions for the whole job on the Internet. It's not difficult but worth reading the steps before tackling.
Edit: Add just a bit of complexity if you also have AC. You may want to leave the job to professionals at that point. Also edited where I said it was on the engine compartment side of the firewall. Looks like it was moved inside. This would explain why I just read complaints of coolant in peoples glove compartments when I was double checking that fact once I reread your post and you said things were redesigned in 05.
That's all I can think of for now. There is a real mechanic on the board who may step up with even more.
Last edited by Murph; 03/29/11 03:00 PM. Reason: corrections
