Speedmeter sensor resistor value
 

My '87 924S speedometer-early 944, part # 944-641-040-00, has a 2 wire sensor on the back, part # 944-641-251-00. When I removed the sensor the resistor was fried-charcoal. The car runs great. What does the sensor interact with? The color code of the resistor is red-black-violet---------yellow. I think it is a 1/2 watt. What is the value so I can get another? I did a web search but don't understand the results. Can I substitute a close value if hard to find? Thanks in advance.

John_AZ:confused:

That two wire out sensor feeds road speed info to the Gallons Per Mile gauge above the tach. The tach should be powering the speed pick off. Does the GPM work?

I had to go out and look at the tach for the GPM-nope-the 87 924S does not have it and the owners manual only indicated the up-shift arrow (CASIS-Computer Assisted Shift Indicator System, I didn't know that either). The 2 wire does plug into the tach and I do appreciate your reply. Now I will not have to get the resistor. How do they say it in German, "if it ain't broke don't fix it".

Thanks again
John_AZ

The two wires still plug into the tach. Interesting.

Now for my second question: What over current condition caused the resistor to blow? Or grounding for that matter.

In other words just replacing the resistor with out finding the cause will just put you back to square one: A blown resistor.

This up shift light must still use a speed reference signal. I prefer the GPM indicator.

SoCAl Driver is correct, The up-shift indicator is not working. I am still going to get a new resistor for the sensor. The dealer cost is $59.95 new unit.

John_AZ