Temp switch sensor thread size?

Does any one know what threads the temperature sensor unit has on 92+ XJ's? Im talking about the one that goes in the thermostat housing. Is it 3/8-18 NPTF?

I have a '90 jeep that's converted to a newer radiator so I don't have the in radiator switch that directly drives the fan relay. Im using a newer thermostat housing ('92+) which has the sensor that (by resistance) tells the ECU its at 220F and then turn the fan on. My goal is to put a lower temperature switch in there which would be easy on the pre '91 rigs like mine becuase they directly drive the fan relay without running through the ECU.

The pre '91 use a switching temp sensor and the later models use a resistive element to feed variable voltages to the ECU.


Here are some ones that switch at lower temp(200 or 185F) but they all have thread sizes 3/8 - 18.. http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1107&prmenbr=361

Unsure of the exact size,but I did use Standard pipe fittings (brass)when i plumbed in a T-fitting.
Wayne

Wayne, which temp switch are you using and what's its temperature on/off range? The one Im looking at is on at 200F and off at 185F. I think 185F might be to low since the 4.0L is designed to run around 195 to 210.

The temp sensor is part of a Turbo-city aux fan switch.IIRC it comes on at 215*. My normal operating temp is 210* w/195* thermostat.
I was told that this sensor is a GM type,1 wire.These sensors are available in various heat ranges,a little time spent in a catalog and you could find what you need.The OEM sensor is 2 wire.
Wayne

Yes Im looking for a switch that turns on around 215 to 210F but can't find the GM one you mentioned at TurboCity.com Some time back I saw a write up somewhere where they used the GM switch but I can't remember which website..

Checked in a NAPA catalog and found these ---
All are GM Fan Switches,3/8x18 npt
FS 110
closes at 224* to 236*, ascending, open(off) at 212*
FS 111, 229* to 245*
FS 112 213* to 229*
FS 113 204* to 220*
FS 115 212* to 218*
All are one wire,and NAPA has wire end to fit.
Wayne

Great, I will check it out. Thanks..