Dome lights come on even fuse 4 is pulled and coolant temp issues

[chucksyellowtj]

So, heater core blew back earlier this year. After replacing it, the jeep runs perfect until we hit 165 temp. Once we hit 165, it goes into limp mode. If I keep driving it, once it hits 185 temp, I can literally drop in neutral, turn off, restart, and it drives fine. Replaced pcm, temp sensor, thermostat, etc. The heater unit stopped working also.
And now the dome lights come on with no fuse. In fuse 4.

Any ideas?

 

[macleanflood]

Any codes on the heating issue?

Have you verified temperatures beyond the dash gauge? What's the PCM say the temp is? How about an IR gun on the thermostat housing?

Tried flushing the system?

Pull the thermostat and put it in water, heat the water and see when the thermostat opens. I went through three store bought ones before I ordered a Robert Shaw from Flowkooler that finally worked and opened when it was supposed to.

As to the dome lights you probably have a short someplace and your going to have to start troubleshooting. Ohm and continuity checks and the Factory Service Manuals specifically the wiring diagrams in section 8w available in the resources section.

Where did you source your replacement PCM?

-Mac

 

[Viking Jeeper]

The dome lights can be manually turned on with the light dimmer switch on the turn signal stalk. One of the most misunderstood things on the TJ is thinking pulling the fuse removes power from the dome lights. It only disables the dome lights from coming on automatically when doors are open or off. They will still come on for a few seconds when shutting down and any time they are turned on with the dimmer switch.

 

[chucksyellowtj]

Any codes on the heating issue?

Have you verified temperatures beyond the dash gauge? What's the PCM say the temp is? How about an IR gun on the thermostat housing?

Tried flushing the system?

Pull the thermostat and put it in water, heat the water and see when the thermostat opens. I went through three store bought ones before I ordered a Robert Shaw from Flowkooler that finally worked and opened when it was supposed to.

As to the dome lights you probably have a short someplace and your going to have to start troubleshooting. Ohm and continuity checks and the Factory Service Manuals specifically the wiring diagrams in section 8w available in the resources section.

Where did you source your replacement PCM?

-Mac

I got the PCM from.Mark at wrangler fix. Going to try the thermostat thing. I've tried a different temp sensor. I read that napa sensors are goodm the one In previous was an autozone. Are Napa parts good.

The other one was an OReileys Auto Parts.


Ill have to check the dome light. It only comes in when I turn off the jeep.

 

[macleanflood]

I did a Napa and an O'Reilly's and all were bad when I installed them and then later verified improper behavior in hot water on the stove.

Flowkooler Robert Shaw dropped in and works perfectly.

-Mac

 

[Viking Jeeper]

Ill have to check the dome light. It only comes in when I turn off the jeep.

By design.

 

[Jamison C]

Flowkooler Robert Shaw dropped in and works perfectly.

-Mac

Temps where they should be? I bought one since Mopars are few and far between. The box said "Drop temps up to 30 degrees" and that didn't sit well with me, especially since the thermostat primarily controls the temp.

 

[macleanflood]

Temps where they should be? I bought one since Mopars are few and far between. The box said "Drop temps up to 30 degrees" and that didn't sit well with me, especially since the thermostat primarily controls the temp.

Dead nuts just below the 212 mark confirmed at the PCM and IR on the thermostat housing.

And that's with a PO installed Napa sourced Spectra radiator and me installed Napa/Gates water pump.

-Mac

 

[Jamison C]

Dead nuts just below the 212 mark confirmed at the PCM and IR on the thermostat housing.

And that's with a PO installed Napa sourced Spectra radiator and me installed Napa/Gates water pump.

-Mac

Thanks, just went with something that seemed like OEM quality that isn't parts store brand. My Mopar thermostat from last year failed open (stamped Motorad unfortunately), so I bought the Robert Shaw and Flowkooler at the same time. Will shelve my OEM as a backup.