Rover 75 M47 2 speed fans

[Sville]

I apologise if this has already been covered, but the fan on my car is not working. I have removed it from the car in the hope of finding the problem. It has a gold resister showing continuity as do all the wires from the pugs to the control box apart from the thin blue one which has intermittent continuity.I am hoping that is the problem. The fan itself runs if connected directly to 12v. I am no electrician and would struggle with any wiring diagrams, but I understand the thin wires control the relays. I would like to know what colour wire controls what.

Many thanks in advance.

[SD1too]

Originally Posted by Sville

... apart from the thin blue one which has intermittent continuity ... I would like to know what colour wire controls what.

Here you go Jonathan:

• Black = battery negative
• Blue/red tracer = control signal, ECM to fan PCB.
• Yellow = + 12v
• Slate (grey) = earth from medium pressure trinary switch.

Simon

[Sville]

I will have another look tomorrow, I work shifts

[Sville]

Hi, I looked again this morning, from the control box the blue/slate wire does not connect to anything outside the control box, just terminating at the rubber wire support. Lower down near the large engine plugs the grey/ slate wire connects to the blue/ red trace wire. Is this correct?

Thanks

[Arctic]

Hi Jonathan.
Sound about right, as the control box of a PWM2 with resistor differs in the fact that the grey/slate wire is sometime connected in the control box.
1

2

whereas sometimes they can be connected further up the wiring loom coming from the control box going to the large plugs, in the control box it shows the grey wire on it's own terminal but cut off as it exits the box.

3

On the M47 control box the grey wire is on it's own terminal but then passes through the control box to the large plug.
4

Therefore it could be one of the relays, or most likely its the PCB board.

Could you add a few photo's of the wiring etc.

[Sville]

I will post some photo tomorrow as I'm at work at the moment. It does look like the third photo. I'm determined sort this out, many thanks for your help Arctic.