Merc 5.7 Sender Unit

[victoryinerie]

If I take a meter and measure the readings at sender unit while the engine is getting hot does anyone know what the readings should be as the temperature changes? I want to compare to the reading at the guage.

 

[Alpheus]

Re: Merc 5.7 Sender Unit

I dont know the linear specs off hand, but on my Mercruiser temp sender, the specs were 80 ohms @ 100 deg F and 180 ohms @ 220 deg F. If my math is correct that about 1.2 ohms per deg. F...

 

[Bud B]

Re: Merc 5.7 Sender Unit

From the manual:

first column degrees C second column degrees F,
last column resistance in ohms

Engine Coolant Temperature Sensor Table
∞C ∞F OHMS
Temperature vs Resistance Values (Approximate)
100 212 177
80 176 332
60 140 667
45 113 1188
35 95 1802
25 77 2796
15 59 4450
5 41 7280
-5 23 12300
-15 5 21450
-30 -22 52700
-40 -40 100700