Help needed - 1988 325is with s52 swap tach and temp not working

[Lunamar]

This car was built by someone else and the temp sensor has never worked when I purchased the car

I was in the middle of trying to fix this and clean up/organize the mess the wiring was in and I did something that caused the tach to stop working
The batteries are new and I sent out the cluster to be checked out again to verify that its not the Si board or the gauges
The wiring was spliced to make a custom harness to my understanding

I have been reading a lot on different forums and so far these are the symptoms;

Temp gauge

1. When the key is turned to the On position ->> the temp gauge jumps to past hot as far as it can, then once the engine starts the temp gauge goes back to the off position
2. I read that if one disconnects the c101 and same thing happens then it’s the cluster if something else happens then there is a problem on the engine side - -so when the C101 is disconnected and the key is turned to the ON position the temp gauge moves up about 2-3mm to just below the first white line which I think is the way it should react normally
3. The car has a brand new brown temp sensor in the block - so unless I got a faulty one then that should be ok
4.On the back of the cluster - I have continuity from c101 to pin 26 at the blue connector
5. No continuity between c101 and the brown temp sensor wiring - so I ran a new wire from the brown sensor to c101 and still no go...same symptoms


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Tachometer

1. pin 47 at the ecu has continuity with cluster blue connector pin 7
2. I see 6.2 volts AC while the car is running for black wire (pin 7) of the blue connector on the back of the cluster so from what I read its not the DME



What are your guys thinking?

Thank you in advance

[Lunamar]

So have been thinking more about lack of continuity on the engine side of the harness for the temp sensor.

and since this was a harness that was made by someone… maybe they wired it wrong and guess what the two brown wires were switched. I can see how the person that wired it made the mistake as the brown wire with the purple stripe on the car side was wired to the same color wire on the engine side but actually the temp sensor on the engine side was one spot over.

Popped both wires out and plugged in the correct brown wire and now there is continuity from the blue connector (cluster-pin 26) through c101 to the sensor ( I did not plug back in the other brown wire (brown with purple stripe on the engine side) as the car side has a thin black wire at the c101 and need to figure out what that wire does---->per my search that brown wire doesn’t need to be connected. Am I correct?

From the search it says the black wire on the car side (m20 325is) is for the speedometer, but my speedometer has always worked. Any ideas???

So, I turned the ignition and the temp sensor moved up 2-3mm - the same way as it did before when the c101 was disconnected.
I started the car and let it warm up, but the gauge has not moved. confused.