944 Coolant Gauge Sensor Testing

[Tom]

Attached below is a 5-slide guide showing how to test the coolant temp sender on a 944.

944 Gauge Temp Sender Testing by Carpokes.pdf

TL;DR Key points in the guide are:

• Up to mid-'84, the sensor had one wire (047.919.501.A)

• After mid-'84, the sensor had two spade connectors (928.606.201.01)

--Wide spade is temperature; Narrow spade is warning light

--Narrow spade is normally open. It should short to ground at 239°F (115°C)

• Temp is measured in resistance (ohms) to sensor body or engine ground

• Temp output scale is the same for both sensor types:

104°F (40°C) = 287.4 Ω
140°F (60°C) = 134.0 Ω
176°F (80°C) = 69.1 Ω
212°F (100°C) = 38.5 Ω
221°F (105°C) = 33.6 Ω
239°F (115°C) = 25.8 Ω
248°F (120°C) = 22.7 Ω