zx6oor

Soon I'll be getting the evap core on my 2000 Cherokee Sport, 4.0L replaced. On forums I've visited, many suggest replacing the heater core also since the area is exposed and the part is relatively cheap.

What other parts (vacuum lines, switches, valves, etc.) associated with making these systems function properly would you suggest be inspected?, replaced, while it's easy to get to?

I know the belt tension over the compressor pulley is important because I've had slippage problems with a 2001 I had before. Last summer, I went through a few parts change-outs on my way to learning the evap core was the issue. I have a new condenser, and my compressor is fine. After doing the dye check with a local shop, he saw no leaks under the hood so I'm assuming all is fine with the hoses, receiver/drier, and such.

Advance thanks to all for your insight/advice.

ST
South Carolina

CCKen

How much money do you have?

As preventive maintenance:

Unless it has been changed in the last few years, you may want to replace your 12 year old HVAC Blower assembly. Not cheap however; a good one is around $144 from NAPA (Continental product from Balkamp).

The Blower resistor block can be changed with the HVAC Unit installed but have it inspected for rust. If rusty, or the connector looks like it has been overheated, replace it. $52 from NAPA (Echllin product).

Have the HVAC Unit air doors pivot points inspected closely, especially the Blend Air Door.

zx6oor

Thanks CCKen for the info. I've been prep-ing for this for a short while, since the end of last summer, so I'll spend what I have to, after good research on parts prices of course.

I saw a video on youtube that mentions the resistor block. Also, there was mention of the a/c temp switch, the associated capillary tube, and the climate control doors and vacuum lines.

Believe me, I only want to pay once in a long while to have the dash out so I'm gonna have that sucker checked out thoroughly b4 it's bolted back in place.

Any others with any ideas or suggestions on what to check, replace, best sites for good parts prices?

The Rooster

also refresh all your dash grounds.. this is free you just need a wire brush and to find them...

zx6oor

Thanks Rooster. I'm sure you've been through yours thoroughly, 20+ yrs and still goin'!

The Rooster

I'm not as old as you may think I'm just keeping the tradition going and the great memories And with the Cherokee if it is on here or in real life you learn something new everyday...

CCKen

The AC/Heater control temp switch can be changed without removing the HVAC Unit so the only thing I would be concerned about is if it works correctly or not (it controls the Blend-Air Door Actuator).

Not familiar with an "associated Capillary Tube".

The resistor block harness connector may be burned up/over heated. Good luck finding a new replacement!

gone4x4

good suggestion--mexican heater core-cheep, all the way around,cheep to buy,made cheep, factory? made very well, not so much on the cheep, i went mexican, and i think i need #3 in less than a year, i will, bite the bullet and go oem, just cuz of the sheer enormity of the repair, good luck!!

zx6oor

I found this on Google. It is actually a post by Abovetimberline, here at CF. His is an 89 model so it's a bit older than mine but it's the most detailed instructions I've seen on dash removal and all of the stuff to take note during the task. Mine may not have the tube.


"This is the a/c temperature switch,it has a capillary tube that is connected to the evaporator that when the evap gets to cold and will cycle the compressor clutch,the way it works is the capillary tube is charged with refrigerant,when it gets cold the pressure in the tube decreases and opens the switch,when it gets warm the pressure expands and it closes the switch,if this switch goes bad your compressor may not cycle,if it fails open it will not come on,just another thing that can cause the compressor to not come on.
If it goes bad you have to remove the lower dash and reach up to remove the screws and pull capillary tube out of evap,then reinstall tube and new sensor"

Click this bar to view the full image.

On the blower resistor, my blower still works and I have all the fan speeds, it's just that while this work is being done, I want to have all these pieces changed out while it's down. CCKen, would you recommend changing out the resistor harness/connector also since it is 12 yrs old?

macgyver35

My suggestions from a similar previous question:
https://www.cherokeeforum.com/f2/im-...2/#post1773393

CCKen

Your Jeep won't have that capillary tube.

You have a low pressure cyling switch that serves the same purpose.

If your resistor connector looks good, keep it. If it looks like it has been overheated I would suggest replacing it. Problem is the harnes/coonector can't be found. If you locate a source let me know.

zx6oor

Thanks macgyver35 and CCKen. Valuable information! If I do find a source for the blower resistor connector/harness, I'll post it for sure .

ST

The Rooster

Well I also been reading on here about LED bulb changes if you have any interesting in doing that now is the time
I just remembered I made sure all the plugs in the wire wall where still sealed good so no all comes in or out...

zx6oor

Ok, I have great respect for you veterans here and the good advice you offer. I hope none of you think I'm cheap after this question so here goes. Do any of you know of a member in the NC/SC area that is "gung-ho" or very enthusiastic about tearing into this kinda work? I'd be willing to pay someone for the trouble, just not $1500! I was at a blog recently where the guy mentioned helping his buddy with his 1998 Cherokee a/c which he described as quite possibly being one of the worst a/c systems ever put on a vehicle. See the link.

http://jalopnik.com/5604307/which-ca...r-conditioning

After seeing this comment, I'm very reluctant to drop a boat load of cash into this unless I can have some confidence about it lasting. I hate to keep beating this horse here but if anyone knows of someone that is a mechanic and does side work or they've done their own work before with success, and they live in the NC/SC area (I'm in Myrtle Beach) it would be great to have a contact.

zx6oor

I just finished with the almost complete overhaul of my a/c and climate control systems. New hoses, accum, heater and evap cores, liquid line and orifice tube, condenser, blower and resistor, blend and fresh air doors, seals, you get the picture. Since the dash was coming off I wanted to do all that is possible/affordable so I shouldn't need to go back in for a long while.

Now, the air is definitely cool at the vents. In 80 deg F ambient, I initially was getting 60F from the center vent. I went back and told my repair guy this. He suggested cleaning the fins of the condenser. He sprayed them out with water hose and said come back if it didn't make a difference. It didn't so, he evac'd the system and charged it again to be sure. I was there, he brought it back to "full charge" and said he didn't want to risk it by adding more. Later as I drove, I did notice the air was just a bit cooler. It was just below 60, say around 57F. The other tech at the shop says that it all depends on ambient temp, humidity, altitude and a 20 deg drop is typical. I'm at the beach in SC so I'm at sea level.

I've checked other forums; jeepforum, wranglerforum, and others. I see performance charts that show a 43-36F degree drop in temp from 80F should be seen, with around 35psi on the low side, which is what we saw on his machine. Is something wrong here? Is this system just inherently short on performance? Do you think maybe his machine may need calibration? I surely don't want to risk overpressurization but I feel that I should be getting better performance.

Any tips, advice highly appreciated.

ST