A/C compressor kicking in with heater (no heat)

Sluder

New member
2001 XJ.

While troubleshooting heat issue, I realized that my A/C compressor is engaging and disengaging every 5-10 seconds. Could this indicate a dash shitch issue that's also preventing my heat from working?

Blend door and motor are working properly.

Heater core hoses removed and flushed both directions

Core exit hose removed and hot water pours out when engine running.

Dash dial changes air to windshield, feet, face properly.

No heat.

Why is compressor kicking in with the heater?
 

Tim_MN

Freakish Hand Strength
NAXJA Member
What is the "heat issue" ? Can you fully describe what happens, and what does not happen, and when all this occurs ? If the controls are set to Defrost, or Defrost/Floor (either of the last two settings on the right), the A/C runs to dry the windshield.
 

Sluder

New member
You are correct. I just found a post that explained the compressor for defrost/feet.

I will post my heater issue in the next post. Any ideas are appreciated.
 

Sluder

New member
Need any help available. Here's what I know so far.

1. Heat blows cold
2. Blend door and the electric box that changes blend door is working. (More info below)
3. I removed heater hoses up near water pump and flushed in both directions with good flow.
4. I removed only the exit hose from core and cranked engine for a moment and had good HOT water flow coming out of core.
5. At one point, after flushing, I started to get heat but it only lasted for a day or two.
6. While I had heat, I removed the blend door controller and verified it works and when I manually turned the blend handle the door changed the air coming out of the vent from cold to hot.
7. While I had heat, I verified the cold/hot dash switch & the blend door were working. Air coming out of vent changed from cold to hot.
8. Im hearing a sound in my upper dash that resembles a ticking clock. It somewhat sounds like a plastic gear that's slipping or teeth broken as it turns but....is there anything like that for the heater in that area? I guess it could be an unrelated engine tick that I've never noticed but sound like in upper dash near middle

Please tell me someone has an idea? Thanks in advance for any info or suggestions.
 

Tim_MN

Freakish Hand Strength
NAXJA Member
Locate precisely the ticking sound, rule it out, or not, as the cause.

If you have no heat, suspect a blocked heater core, or rusted away fins on the water pump and no coolant flow at low rpm's.

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