Temp guage inop

[Grant01]

so after having my fuse 10 bake its self, my temperature guage is non working. i swapped the harness and traced the wiring back and all is well with the wiring. considering i had my fuse 10(fuse to the guages) bake itself due to a short, do you suspect the guage could be bad or possibly the sensor. it was working before the i swapped the harness and before i had the fuse issue

[xLegendOZWest]

i have the same question, but i think the reason mine wont work is because of me having the three wires in the wrong spots on the temp sending unit.

[bmwdready347]

Same here mine worked and then it just stays in red even when engine is cold

[etxxz]

A wire coming from your adapter should go to the temp sensor. To be exact, C101 Pin 4 goes to M20 "Brown Top" water temp sensor, sensor ground through head. C101(4) goes to dashboard temp gauge.

OBD1 vs OBD2 head:
OBD1 head has two sensors. One for the computer, one for the dash. Replace the one for the dash with the M20 sensor. Actually threads are different so whichever fits the M20 sensor, replace thatone.

If you have an OBD2 head, there is only 1 temp sensor. In this case, you need to drill and tap the head where the OBD1 head has it. Technically its the same casting, just that machining operation wasnt performed. Did i loose you guys here? In other words the M20 Brown Top water temp sensor is there just for the dash.