Question for you Jeep Mechanics.......

Posted by: michael_d

Question for you Jeep Mechanics....... - 03/27/11 04:10 PM

The girlfriend has an 05 Jeep Grand Cherokee. The heater is broke. Everything functions correctly, but the air does not get hot, or even warm for that matter. The dealer says it is most likely a part that has failed (of course). The offending part costs about $100, but labor hours to change it are 8 to 10 because the dash must be removed to get to it. At $150 an hour, that's enough motivation for me to fix it.

I've been searching this phenomena, and there's very little info to be found on the 05 or newer models. Jeep completely re-designed the heater in 05, otherwise, the repair would be pretty simple (blend door replacement).

My first question is; anyone know where there might be a step by step guide for pulling the dash on this Jeep. The second question is; where can I buy a good service manual that will have the instructions?

I've gone down this road before, pulling interior panels and things apart and it was bumpy at best. There's always an easy way to get fasteners apart, then there's my way, break stuff. I want to try the easy way this time....
Posted by: Murph

Re: Question for you Jeep Mechanics....... - 03/29/11 10:20 AM

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.
Posted by: michael_d

Re: Question for you Jeep Mechanics....... - 03/29/11 11:03 AM

Thanks. Sound advice. Unfortunately, I've already made all those checks, which is why I know I need to tear the dash out to get to the blend door, or blend door controller or motor. I've been searched all over the place for a service manual for this stupid thing, and have not been able to find one.
Posted by: Murph

Re: Question for you Jeep Mechanics....... - 03/29/11 11:03 AM

Edit: Oops, I posted this as you were posting your reply. I'll leave it just for fun.

Found a great picture for the thermostat location on a WJ' 4.7L engine. I'm guessing the 5.7L will be close enough for it to generally apply as well.

Posted by: Lampshade

Re: Question for you Jeep Mechanics....... - 03/29/11 11:12 AM

All Data DIY is a subscription to 1 vehicle only for about 20 bucks. There is no guarantee the info will be there but it can be really helpful.
Posted by: Murph

Re: Question for you Jeep Mechanics....... - 03/29/11 11:18 AM

I figured you probably did check those items but they were not mentioned so I threw them in the ring.

I have a PDF version of the service manual on my home PC. I will have to double check for 2005 but I think it is there. However, it's likely over 85MB in RAR format. If there is somewhere I can put it for you, you are welcome to it.

I suppose I could temporarily set up a FTP site on my home PC if need be. Probably shouldn't be sharing electronic versions but it would be no different than loaning a buddy a written copy. Nobody ever worries about that.
Posted by: michael_d

Re: Question for you Jeep Mechanics....... - 03/29/11 11:33 AM

Well if you have the section for the heater, I think that would enough. Thank you for the offer, it is very generous.

The Jeep is nothing fancy, just the V-6, with manual heater controls. I hate the POS and have been trying to get her to get something different for years, but she won't.
Posted by: Ken.C

Re: Question for you Jeep Mechanics....... - 03/29/11 12:25 PM

Looking around on Amazon for Chilton and Haynes manuals, I did find them for that model, but they are very poorly reviewed.
Posted by: jakewash

Re: Question for you Jeep Mechanics....... - 03/29/11 03:30 PM

Manual? You don't need a manual, just start taking away the layers. Just be sure to disconnect the battery for a few minutes before touching anything, wouldn't want the air bags to accidentally go off.

I have found the temp doors tend to crack in the 'D' opening at the end of the actuator doors.
Posted by: Murph

Re: Question for you Jeep Mechanics....... - 03/30/11 08:10 AM

I do have a manual for an 05. I have a lot of Jeep manuals for some reason? crazy

I did however, forget to do anything with it.
I've never broken out an entire section of a pdf file before. Is there a proper tool to do that? I suppose I can just copy those pages into a word doc or something. In the mean time, PM me your email and I'll get what you need into a manageable file size one way or the other.