¾” Deep socket/wrench
Coolant Temperature Sender (Part Number DAC 2583)
Connector (Calterm # 08653)
2” x ½” Heat Shrink Tubing
6” x ¼” Heat Shrink Tubing
Self-fusing Silicone Tape
The Coolant Temperature Sender is used for the dashboard Temperature Gauge. It is located on the right-side coolant rail, near the front (above the thermostat), and the plastic part of the stock piece is green. Don’t confuse this with the Coolant Temperature Sensor (which is used for the EFI system and is located on the left-side coolant rail), the Low Coolant Sensor (located on the Header Tank), or the Coolant Temperature Switch (used for the Auxiliary Radiator Electric Fan and located on the Water Pump). The word “Water” is sometimes used in place of the word “Coolant” for all these devices – jeez…
This device is essentially a resistor that changes it value as temperature changes. It is easy to test using an ohmmeter, just pull the plug and put the meter across the two terminals – Doug Dwyer and Alex Cannara detail the values on www.jag-lovers.org/xjlovers/xjfaq/testcts.htm. Although mine seemingly measured ok, I was doing so much other coolant system work this past winter that I thought I might as well replace it.
I got a sender from Motorcarsltd.com (their part number IN101930) for $31.79. I changed this when I had the cooling system drained, so I didn’t have to worry about coolant spilling out. Given its position behind the thermostat, I doubt much would come out anyway even if the system were full (as is the case when removing the Auxiliary Air Valve). When replacing it, don’t forget some anti-seize compound on the threads.
Of course, the connector was old, brittle, and cracked – time for a new one. It is the same connector used on the Fuel Injectors and elsewhere in the engine compartment. My local parts shop had a couple of Calterm #08653 “GM Multi-Port Fuel Injection Sockets” in stock ($2.23 each) that is an exact fit. Another parts store had an equivalent connector for $7.50 each – watch out.
The Calterm is black with two white wires about 6” long coming out – no “boot” supplied. I used an X-acto knife to trim the top “barb” on the connector in order to fit the ½” heat shrink tubing over it to make a watertight boot (by heating the tubing with a lighter). I then put ¼” heat shrink tubing over the “boot” for nearly the entire 6” length (leaving the bare ends of the wires exposed). I cut off the old connector near where it splits out of the harness, stripped back the wires, and soldered on the connector (polarity does not matter). I shrunk the ¼” tubing then used self-fusing silicone tape (from my local Sears Hardware store) to insulate and wrap the connection. Plug it in. Next project…
Questions/comments: Email me.