Hi all,

When I bought our Multipla the fan had stopped working and had been bypased with a home made relay and switch affair. It worked quite well but I want to return it to original.

Apart from the aftermarket wiring the fan motor resistor was unplugged, and when I removed it found it didn;t look like the original. Instead of the expected finned alloy unit there was a large square block, it looked very old school!

First of all was removing the aftermarket wiring and tracing where it went to. The feed had been taken from the fat orange wire that goes to the fan motor. With the excess wiring removed I reconnected the orange wire. I was hoping that in the dim and distant past the heater motor resistor had failed, been replaced with an incorrect type and then bypassed. With the correct resistor installed and the original wiring repaired I turned the knob and..... nothing!

Further investigation showed a thin black wire behind the heater control panel had been cut and earthed so I reconnected it. Also, with the ignition on the air con and recirc button lights flicker but then go out after a minute or so. Earth fault?

My test lamp flickers when I put the probes across the plug terminals for the fan, showing there is a low voltage there, but presumably not enough to power the fan.

I found that if I earthed the earth side of the fan or the metal resistor body the fan will run on full speed.

Does anybody have any idea on what my next step should be? I'm thinking that the control panel on the dash could be faulty, I have a spare but is there any common failure point I'm missing?

Thanks for reading!!:devil:

I went out tonight for a prod, and to scratch my head. I set up my test rig, comprising of a spare fan motor and the resistor pack, plugged it all in and found it still didn't work.

I then tried to separate the infamous multi-plug which seemed to have got hot and fused together. After attacking it with a kitchen knife and getting nowhere I tried the fan knob again and it worked!! All the speeds work along with the aircon and outside temp display. I cut the old connector block off and crimped the wires together. Great!

The servo for the temperature flap was in bits, held in with self tappers and completely dead. A rummage in my pile of spares found a new servo and screws. With it fitted we now have running hot and cold air. Yay!

I feel very pleased with myself, Thanks to this forum I've managed to fix a rats nest of bodged electrics and get something working when the last guy failed.

Let's see how long it lasts!