Need advice regarding my heater

So, when I bought my XJ the blower didnt, well, blow. I traced it back to a melted wiring harness and repaired it all. So, now the blower works again.

However, the guy who had it pretty much screwed everything up with the heater controls as well, and so nothing on the panel actually works.

So, what I'm trying to figure out is .. at least for now, what can I pull, prod, ducttape so that it just blows hot air.

Under the right glovebox, there's an actuator (not sure if the right name) that has a rod going through it that pushes a big flap with foam up and down. I'm assuming that pulls outside vs inside air?

Next, on the left hand side of that actuator (above where your left leg would be if you sat in the passenger seat) there's a wire going to a rod. If you push it out farther it seems to blow straight cold air so I'm guessing thats the "Vent" setting. If I pull it back then I don't get straight cold air, but its not hot either .. just seems like its in the 60's.

Anyway, any advice you may have is appreciated .. its snowing out and I'm trying to get this beast running so I can use it. Thanks!

You are correct about the recirc door. It allows inside vs outside air. I believe it is designed to only work in the max A/C position which won't help you get warm.

The other rod is possibly the blend door. This is what mixes cool air from outside through the evaporator core with air warmed by the heater core.

Try reading this link for more info:
Core flush

I've done this to all the XJs I owned and it works well

The 89 will have the cable actuated blend door, which will be right beside (to the right of) the center console behind the lower dash panel.

Hard to describe the position really, but you will see a lever and a cable leading to the HVAC controller. If that cable still exists, in your case....

Beneath the driver's side dash to the left of the center console/heater box you will find 2 vacuum actuators. You can play with these. I believe one controls the lower vents and one controls the middle vents.

I'm not sure where the actuator that controls the windshield defroster is, but regardless, with a lack of vacuum it will default to defroster mode.

Ok, it's defaulting to defroster mode so it must be a vacuum issue thqats causing my entire heater panel to not function and the actuators from controlling the cables and rods.

Sounds good on the heater flush. I'm wondering if any shops do that kind of work? The reason I would consider it is that its 6 degrees out and the garden hose is frozen over. My rig's scheduled to go in to the shop on Tuesday to get a replacement steering setup, alignment, tires balanced, etc so I was thinking if shops typically do that kind of thing it might make it easier. Plus I can bring a $5 thermostat with me and get that swapped out too.

I'm crossing my fingers that the heater core isn't out! ... pulling out the dash doesn't sound fun.

Your blend door is not vacuum actuated, so even if you have a problem with your vacuum the blend door will still be controlled.

Vacuum controlled blend door came in 97.

You can also feel your heater hoses under the hood. If they are both hot, you must be getting coolant flow through the heater core. (So flushing isn't really needed.)

I'm not home for the weekend, but I'll feel the hoses and see what I get.

Left door (under passenger side) has a cable going to a rod, the other has a vacuum actuator. If the cable control is not vacuum driven, then I'm guessing something is not connected right from the dash controls or the cable snapped in the rubber guide. I'll definitely look at fixing this stuff long term, but for now I'm just hoping to jimmy rig this thing to blow hot air since its 6 degrees and snowing out.

I appreciate all the responses =) I'm going to test things Tuesday morning when I get home and see what I get!

Here's the vacuum schematic for the doors. If you can reach them, you can push on the door arms and see if the airflow changes.



As the others said, the blend door is cable operated. You should hear the door hit the stops at each end when you move the temp selector from fully cold to fully hot.