thermostat reading

hey guys, i've tried looking for some info but cant seem to find wat am looking for. Is is normal for the temp guage to never go anywhere close to the halfway mark......i've had it for 2 years and it is always around the 100 reading or a little higher....yet i live in florida where it gets real hot sometimes
do i need a new t stat?

You may need a new temperature sender, or you may need a new gauge.

Before you ask "Where's the temp sender?" -- the answer is "It depends." To answer that question we need to know the year of your XJ and what engine it has.

I had a thermostat fail in the open position. (note: never buy a failsafe for an XJ) It stayed at 50C (equiv to about 100'F) no matter what the ambient temperature was.

It's easy to check, pull it out and see if it is stuck open or missing.

Bottom line is that even without a tstat your temp should get over 100 after running for a while. Sounds like the temp sender or guage.

Depending on year, it could also be a faulty ground on the instrument cluster.

A couple of years ago I went through several rounds of replacing the oil pressure sender because my oil pressure had suddenly gone down about 10 psi from what I thought it "should" be. The I noticed that, although I was running a new factory 195-degree thermostat, my temperature gauge ran just barely above the first tick mark on the scale (not the 100-degree mark at the bottom end, but the first tick above that). The scale is not linear so I don't know what temperature that indicates ... but it ain't 195+.

Then I noticed that my voltmeter was indicating just barely above that first tick at the upper edge of the red zone, which is barely 12 volts. But if I plug a voltmeter into the cigar lighter it reads in the middle of the "Normal" range, and if I put a multimeter on the battery with the engine idling it reads 13.8 to 14.1 volts.

The bottom line is, it appears that all of my gauges are reading approximately 15 degrees of dial sweep lower than they should, and I've read reports on this forum of people who have corrected faulty reading gauges by adding a supplemental ground strap to the gauge cluster.

It's something to consider. I haven't pursued it for lack of time, but I think I'm going to have to because the voltage gauge, especially, seems to be getting farther and farther away from the true voltage.