86 735i coolant gauge not working

[e23inco]

Hi,
I am trying to get my temp gauge working again......here is a brief history and symptoms:

1) i've owned the car for about 19 years....it used to work sporadically
2) rodents were in my engine bay several years ago, and ate a couple wires - one of the wires was on the sending unit. so, i bought a new connector and put it back on. i am not sure if this is when the gauge on the cluster stopped working or not, but it has not worked since.

I just replaced the sending unit and the coolant temp sensor, and put on a new connector again (for the one the rats ate through).

here is what it does when i turn on the key....the gauge moves up a little, maybe an 1/8th of an inch, and it never goes any higher, regardless of how long the engine has been running.

does this sound like an instrument cluster issue, or something else?

thanks,
andrew

[BONDOSPECIAL]

The spade connectors for the two pin coolant temp sensor are different sizes. One is a 0.25” spade and the other is 0.187”. I am guessing you used 0.25” female spade connectors when you repaired the ends. This would allow you to connect the wires to the wrong pins on the sensor. Try flipping them. It matters which wire goes to which pin. One pin is for the cluster gauge and the other is a signal for the automatic climate control.

[e23inco]

The spade connectors for the two pin coolant temp sensor are different sizes. One is a 0.25” spade and the other is 0.187”. I am guessing you used 0.25” female spade connectors when you repaired the ends. This would allow you to connect the wires to the wrong pins on the sensor. Try flipping them. It matters which wire goes to which pin. One pin is for the cluster gauge and the other is a signal for the automatic climate control.

suprisingly enough, the rodents only ate the smaller of the two connectors - so the original larger connector was not damaged, but the smaller one i had to replace.

here is a picture.....

[BONDOSPECIAL]

If you used a normal (0.25") size female spade for the smaller terminal, make sure it's making good contact, you might have to use a pliers to crimp the rolled tangs tighter.

[e23inco]

If you used a normal (0.25") size female spade for the smaller terminal, make sure it's making good contact, you might have to use a pliers to crimp the rolled tangs tighter.

thanks, i will give that a try.....