Temp gauge issues.

[Wickedpissahe30]

Alright guys.. recently did a m50 swap into a later production 85 325e.
I have a brand new brown m20 temp sensor in place the black one.(2nd location between the blue one and TB heater line)
I tried another known working one from another car and no avail.
I also swapped in a i cluster for the 7k tach.(yes it’s working the the so batteries aren’t dead)
When I put the key in the on position the gauge goes full hot. When I start the car the gauge stays at full cold, even when the heats blowing fully hot.
I checked the c101 pins, the e36 harness x20 and also the harness adaptor I’m using.(from garagastic)
I’m not sure what else to check or where to go from here. Can anyone point me in the right direction?

[IRON-E]

Alright guys.. recently did a m50 swap into a later production 85 325e.
I have a brand new brown m20 temp sensor in place the black one.(2nd location between the blue one and TB heater line)
I tried another known working one from another car and no avail.
I also swapped in a i cluster for the 7k tach.(yes it’s working the the so batteries aren’t dead)
When I put the key in the on position the gauge goes full hot. When I start the car the gauge stays at full cold, even when the heats blowing fully hot.
I checked the c101 pins, the e36 harness x20 and also the harness adaptor I’m using.(from garagastic)
I’m not sure what else to check or where to go from here. Can anyone point me in the right direction?

Maybe your temp gauge on the tach is loose, try tightening and add a little loctite, hopefully it does the trick.

[Wickedpissahe30]

Maybe your temp gauge on the tach is loose, try tightening and add a little loctite, hopefully it does the trick.

I tried that on both clusters and it didn’t work. That was actually one of the first things I checked.

[IRON-E]

Than something to do with the wiring.

[Wickedpissahe30]

Still can’t figure this out. Checked the c101, the harness adaptor and the e36 harness x20. It all seems to be correct. The only thing I did find was that with the key in the on position I have 5volts at the c101. At the harness plug for the temp sensor I have 12volts. But it doesn’t make sense, I checked the pins and they’re going to the right spot

[e30austin]

Definitely something to do with the wiring. Double check your pinouts.

[Wickedpissahe30]

Definitely something to do with the wiring. Double check your pinouts.

I have 3 times and I can’t find anything wrong. I’ve check the c101, the x20 on the e36 harness and the the harness adaptor

[IceWhite]

Disconnect the connector at the brown temp sender. (This wire that goes from the sensor to the gauge in the cluster is usually a brown wire with a violet stripe.)

Now, connect a separate length of wire from the brown temp sender, and tap into the brown/violet wire just before it goes into the cluster. Turn key to see if there are any changes.

[Wickedpissahe30]

Disconnect the connector at the brown temp sender. (This wire that goes from the sensor to the gauge in the cluster is usually a brown wire with a violet stripe.)

Now, connect a separate length of wire from the brown temp sender, and tap into the brown/violet wire just before it goes into the cluster. Turn key to see if there are any changes.

I was thinking about doing that. I’ll give that a try and see what happens