OK..it looks like I can do it without that harness. They are doing it like I did on my '75 El Camino, with a relays for high & low beams. I have all the wiring I need to do this, which is aircraft Mil-spec stuff....

 

I picked up that fan clutch (272310 from Napa) yesterday, and got it installed this morning. That was the ONLY THING that I have installed on my jeep so far that was zero hassle, was kinda nice. Except that it didn't fix the issue. During my test run, it did take longer to reach 210 degrees (keep in mind I have a 180 degree thermo so I shouldn't be running that hot.) However, when sitting in park/neutral, or even driving, higher rpms (2.5-3k) will lower the temp. This leads me to believe that either my water pump isn't working to full capacity or my thermo isn't working properly. Am I correct in my thinking?

 

A lower temperature thermostat won't necessarily lower your overall running temperature it will just open sooner. In the summertime, even with a 195 degree t-stat, an XJ will have the thermostat fully open most of the time. A thermostat controls the MINIMUM temperature of the water inside the block at full operating temperatures. It has little to no effect on the maximum temperature the system will reach.

How hot did it get? You mention 210 degrees, but that's a pretty normal temperature for an XJ. What was the ambient temperature when you tested?

I would agree that water flow is likely your issue, if you have one.

 

It got to about 217 I would say, it's hard to be exact when there's only 3 numbers on the actual gauge. It was about 40 degrees out.

 

Do yall think it could be a head gasket issue?

 

I'd do a GOOD flush and a water pump before I'd do a head gasket.

 

Don't rely on the dash gauge for any accuracy. Use an IR temp gun or an OBDII scanner.