E30 Zone

Ive had to replace the resistor on my air con system but I have a few problems and questions....

1. The new resistor is different to the old one in apperance and make (new one Bosch, old one Seimens) and therefor will not fit in the place of the old one, does this matter?

2. The new one has a metal bracket on it, is this just to mount it with or is it also used for earthing?

3. I gave it a test run with wires bodged on (temporary) to see if this did fix the prob with the fan, it did but the resistor got hot and melted some of the electrical tape I had on it to hold it in place. Is it normal for resistors to get hot?

4. Is the new mounting point ive found suitable? (see pic)
-- Please ignore the wiring - this is very temp while I find suitable connectors (anyone got a BMW part number for them?) --

This mounting point is on the right of the aircon fan.

No earthing required.
Resistor gets hot and should be mounted where it gets some airflow.
If the fan has partly seized, it will draw excessive current, and the resistor will run hotter and have a shorter life.

Thank you, youve put my mind at rest. I was worried that I might start a fire while sitting in traffic with the air con on.

Ive just got to connect it properly now and see if I can find a slightly more suitable area to mount it.

Thanks again, I probably should have asked the questions before playing with the electrics though!

Steviec wrote:Ive just got to connect it properly now and see if I can find a slightly more suitable area to mount it.

My car has the siemens resistor (gold coloured aluminium job), but when replacing it, I was unable to remove the very rusty screws, that secure it to the fan shroud. After drilling out the screws, I made a small mounting plate from 6mm ally, and screwed this to the fan shroud. I then drilled/tapped some new mounting holes in the ally plate and screwed the resistor to this.

As well as being a nice repair, it also helps to cool the resistor.

Ian.