My rear heater blows cold all the time. It never gets hot. Rear A/C seems to work fine. What can I do to get hot air for the back seats. My kids are suffering this winter. Thanks for any help.

 

[updated:LAST EDITED ON 24-Jan-02 AT 06:16 PM (EST)]Ya checked your coolant level?


Don't take this the wrong way, but are your SURE that rear controls are on hot. Sometimes guys will put the front switch on "REAR" position and the rear controls are on cold. (kids)


You may have blockage in the lines that take the coolant to the rear heater core. I know of a messy way that you can check if you want...

 

I had my coolant levels filled this summer. At the risk of sounding ignorant, how does coolant affect the heater? And, I did check to make sure everything was on hot. Is it easy to check the heater core to see if it functions correctly? Is it easy to replace the heater core?

 

>I had my coolant levels filled this summer.

Did you have your coolant changed?

>>At the risk of sounding ignorant, how does coolant affect the heater?

The coolant from the engine, when warmed, is sent to the rear heater core via lines underneath the passenger side of the truck. I'll have to check if it's true for the X, but on my van the rear heater core is HIGHER than the radiator so some special [/i]priming[/i] procedures are needed to ensure the core is filled. Also if the coolant level drops too low that is the first thing to lose the use of available coolant.

>>And, I did check to make sure everything was on hot.

I figured as much. But htought I'd ask. Now, you made sure that the switches arren't faulty too right?

>>Is it easy to check the heater core to see if it functions correctly?

Somewhat, open the panel in the rear. The one that has the jack in it, also houses the rear heat/AC. Turn on the rear heat and feel the hoses for warmth. You may also feel coolant pass through them. You may also want to feel the hoses from underneath your truck.


>>Is it easy to replace the heater core?

I'd make sure that the coolant is geting to it first. For a heater core to be labelled as "need to replace" is should be leaking. It's just a little "radiator". Although it could be plugged, the somewhat scientific test above should give some indication.


Let me know...


Ken

 

Correction, it looks as if the lines are on the driver's side. I'd go and look on my X but I'm home alone with the kids today and my driveway is a solid sheet of ice. So, I'm looking at the manual.

I also think that the "blend" door within the rear Heat/AC unit could be a culprit, as this door moves UP to expose the air to the heater core. I don't know if it it serviceable. Nor do I know, without going to look for myself, if there is a way to expose it for inspection. When the wife gets home I'll go have a looksee.

I'd also look at all the electrical connections back there to ensure that they are tight. Maybe somethin' came loose. If you've removed the jack or anything else in there, something coulda got hit.

Keep us posted.

 

Hey, I appreciate all the help. I like to do things myself but have no idea what I am about to undertake. All this information is great. I will check under the truck this weekend. Can I figure out which are the hoses by following them from the front radiator to the back? What was that messy way to check for blockages in the lines? I did not change the radiator coolant, though I have purchased new coolant and additive. Mine is a diesel, in case that makes any difference. Thanks again.

 

[updated:LAST EDITED ON 25-Jan-02 AT 06:08 PM (EST)]A correction to a correction.


The rear heater lines are indeed on the passenger side. The driveway thawed and the kids napped, so I verified. Look up above the tailpipe and you'll see 'em enter the body.

>>What was that messy way to check for blockages in the lines?

Pull the lines off when the truck is running at operating temp with the heater on. DON'T DO IT! That stuff is HOT!

Just feel the lines (they are made of regular heater hose not the steel?/aluminum? A/C lines) If they are hot when they enter and exit the body then the malfunction must be with the blend door or the connection which cause it to actuate.

If not, the problem lies elsewhere.

Keep us posted!

 

Okay, I checked the lines. They indeed do get hot. I noticed also that some of that black goop on the aluminum pipes has dripped off and that there is air escaping from the general area where the two pipes enter the black plastic area that seems to house the fan. should that be airtight? also, I wiggled all the electric connections and, for the first time, I felt lukewarm air coming out the rear vents. Not nearly as hot as the front heater but not as cold as the outside air. Barely warm. But, the hoses did indeed get rather warm. So it looks like the door. Now what? This, by the way, is very interesting. Thanks again for your efforts.

Eric

 

>>I noticed also that some of that black goop on the aluminum
>pipes has dripped off and that there is air escaping from
>the general area where the two pipes enter the black plastic
>area that seems to house the fan. should that be airtight?

I would say yes.

>also, I wiggled all the electric connections and, for the
>first time, I felt lukewarm air coming out the rear vents.
>Not nearly as hot as the front heater but not as cold as the
>outside air. Barely warm. But, the hoses did indeed get
>rather warm. So it looks like the door. Now what?

If it's under warranty and you trust your dealer, go show the service guys. They should replace it. Sounds like you found the problem. Good job!

 

Unfortunately, I bought it used and only have warranty remaining on the engine. So, I am going to fix it myself or have it fixed. I am going to try and figure out how to remove the interior paneling to expose that entire assembly. If you have any hints regarding the rest of the process, I am listening. Thanks.

 

>Unfortunately, I bought it used and only have warranty
>remaining on the engine.

What do you mean, remaining? Are you over mileage (36K)? Is this "engine" warranty provided by the dealer that you bought it from?

I can tell you the process on now to remove it. In fact, send me your e-mail and I'll send you the process including drawings.

monsta@excursionowners.com