405 issues heating A/C fan

It's bloody hot in Melbourne at the moment and there is no sign of abatement.
To the point.

Internal fan not working.
But remove it and solid wire 12volts and voila! It goes-flat out.:headbang:

Now I know what you're thinking! It not the $180 electronic controller because on professional advice I bought and fitted a new one.

On checking the 4 pin connector this is what I am getting
1 orange = 0 volts
2 black = earth
3 brown = 0 volts
4 red = 12 volts

On pin 1 & 3 as I slide the fan spees control across it full range (ignition ON)
ther is no voltage change as I would have expected.

I suspect a fuse, but as I don't have a handbook/manual does anyone know the position of the fuse and its value?

A friend who should know about these things suggested a power transistor that may have gone to lunch. But where is it on a 405 and is there an easy test?

How likely could it be an issue with the slider control (series 2 405) ?

Any other thoughts?

Please!

Predicted temp tomorrow 40 degrees in the shade!

Don't understand what's going on here.
Is it hard-wired and going flat-out, or does it not go at all ?
The orange and pink (?) wires will only have low voltages on them when the engine is running.
Don't know the voltages or fuses, but can look up.
It's not likely that the fault would be in the slider control area.
The speed control transistors are on the underside of the motor.
They go short and cause the motor to be flat out all the time.
If they are short, they measure short between the outer case and one of the 2 pins, don't know which without seeing.
All this is for the Xantia, and I hope that the 405 is the same.
Despite having 12 Volts on the red wire, I would still suspect the ignition switch to cause the fault, a very common stunt on the Xantia.

Story here:

http://www.aussiefrogs.com/forum/showthread.php?t=31216

And have a nice, summery day in Melbourne tomorrow.

And how come the emoticon finished up at the top ?

The early 405 fans sufferd from water from the A/C units and there is a relay below the power transistors that fails.. you can clean the relay contacts some times and it works other times you have to mbypass the relay

Hope this helps

I had a similar problem with mine when it was 40*C in Sydney recently.
I replaced the PLUG on the RED wire that connects to the fan motor.
I cleaned and twisted the male part slightly to enable the fitting of a larger plug( didn't have the correct size). Instant cure, and hasn't faulted since.
Easy job with satisfying results.

.

I think its fuse number 18 and its 25 amp. I know this because mine just blew, about to try and fix it! It will tell you in the handbook what number fuse controls what.

405 heater fan

Thanks for the feedback so far. I will go hunting the fuse and I'll try your location, luchcutter. Could you please check as I DO NOT have a handbook! That is the frustrating part of the fault.

My fuse #18 is 10amp and appears OK!

The power transistor is in the fan motor housing.


Sounds like the fan itself is ok as you can run it direct off 12v


On the 4 pin connector... Pins 1 and 3 go to the sliding fan speed control, There is no voltage here, only resistance which will vary as you operate the fan speed control. so unplug and check with an ohm meter This resistance alters the bias on the transistor which controlls power to the fan. If the resistance varies and the plug in connected properly... sounds like the transistor has gone open circuit ( if the fan doesnt work) or shorted ( if the fan runs flat out).



Any warranty on the controller/transistor if it has to be replaced??



Decca