406 D8 Interior fan playing up

boodek

boodek

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Wodonga and Euroa, Victoria, Australia
Hello all,

I've searched high and low here and elsewhere on the internet and can't really find a issue similar to mine.

My 1997 406 ST (2.0L, 80,000km) with the manual ventilation controls developed an issue a couple of months ago where the interior fan stopped working properly. I could move the fan speed slider up and down and it would only work on high speed. The D8 has the resistor module bolted on to the fan assembly and is quick and easy to change, so I picked up a new module off eBay and installed it which fixed the problem for perhaps a week or two, but once again it stopped working except for high speed. As the resistor module was quite cheap I bought another and fitted it, just to prove whether the prior replacement was faulty or not. The new one has done the same thing and stopped working on anything other than flat out after about two weeks.
Obviously the fault lies elsewhere, but I'm struggling to find information about the manual D8 setup - there is plenty around for the auto D9 ventilation. I'm measuring 12v at the main supply to the fan when the ignition is on but am not sure of the feed to the 4-terminal plug Does anyone have any ideas please?

Thanks.
 
I've seen similar issues with the Xantia and 605, in the end I decided it was the brushes/commutator at fault. Replacement brushes are cheap, so this is worth trying.

Of the four pin connection, the fan motor's ground is modulated by the control board with power being spent as heat by the trannies in order to vary the speed.

I'm assuming you've checked the fan motor supply at all connections between battery and fan for burnt contacts and loss of contact "tension" - feel for heat as the fan runs.
 
This issue sounds very much like the problems we used to/still experience with 505 interior fans - if it's brushes. It doesn't seem to have a huge impact on what the mileage is, though obviously higher mileage cars would be expected to have worn down.

I'm thinking of our 1999 406 ST which gets used every day but doesn't do much more than 10-20 km per trip - on a good day. This car is now coming up to 160,000 km, but I've replaced many more bits and pieces (internal electrical components) than on my 1998 SV, which gets much longer runs. What the ST's history was before we got it I can't say, but it was a country car, so there wouldn't have been interminable times sitting in traffic jams with the fan going.
 
The 406 is a country car, bought originally from Baker Motors Albury by a cockie from Gerogery and driven by him for the first 74,000km. I bought it from Blacklocks in Wodonga nearly two years ago and have put about 6000km on it since. Mind you, much of that has been short around-town trips which would mean the fan is stopping and starting frequently. So, I suppose I check the fan brushes next - will I need a new resistor module as well? Is it worth checking the fan slider control too?

Addo - all connections appear fine.
 
I would try to clean then crimp/tighten those electrical connections, all my fan problems on my 307 went away after I did that.
 
I've pulled the brushes out and they are down to about 13mm long (measured halfway along the arc). The commutator is definitely worn but doesn't appear to be bridging between segments so I'll leave it alone for the time being. I'll grab some brushes from the local rewinder and fit them when I get a chance, maybe by the weekend.
 
My fan problem was similar and it was attributed to the white wiring connecting plug. It had slightly melted over the years and was intermittently breaking connection.
 
I've had:

- The connector melt/break - resolder a new one in from a wrecked car.
- The fan die - new item. Wasn't cheap from memory.
- The slider on the control unit wearing out - cheap control unit off a low KM wrecked car.

I think the car is on 235k now - I gave it to my dad : )
 
I've finally gotten around to having another go at fixing this issue. I put some new brushes in - it made no difference as the fan still ran flat-out or nothing. Interestingly, if the speed slider was moved off maximum and then back to maximum, the fan wouldn't always work.

After replacing the brushes I gave the motor a test run on the bench, hooked up to a battery for five or ten minutes, it worked like a charm.

So, I put another (new) resistor pack in, connected it all up and turned the ignition on. The fan kicked in about halfway along the slider (to a very low rotational speed) and at maximum on the slider the fan was blowing only moderately. I switched the whole lot off in disgust, and came back out about half an hour later to try it again. It was back to its flat-out-or-nothing behaviour again.



Any ideas, anyone? Please? I can't find any signs of overheating connectors anywhere. Is it a dodgy slider?
 
Looks like nobody knows. Unfortunately I think I'm about to be confronted with the same problem on the 1998 D8 STDT. I passed the car on to my son when he got his licence last year. It's now done over 450,000km. He came home yesterday and said the fan stopped working but came good again the next time he drove the car.

I did finally find a solution (of sorts) to the central locking problem that's been plaguing it for a few years. I was never able to find the cause of the fault which prevented the doors being locked either remotely or using the key in the door lock. If you tried locking it manually from the inside, the actuators would immediately unlock it. Pulling the fuse identified as "Central locking" made no difference, at all - which I thought strange. A couple of weeks ago I found another fuse listed as "Central locking alarm", a feature which it doesn't have. Removing that fuse eliminated all lock actuator function and you can now lock and unlock the car like you could in a proper Pug like a 504. Just push the button, hold the handle up, and shut the door. But now the radio doesn't work!
Bloody unnecessarily complex car electrics.
 
The latest installment with this saga happened today. I pulled the ignition switch/barrel to bits and it looked as good as new - no signs of overheating or melting anywhere at the barrel or any connectors downstream. I also pulled the ventilation controls out and stripped them down to have a look at the fan slider contacts. They were as clean as a whistle but were given a spray with contact cleaner and a wipe over with a clean cloth anyway before reassembly. The whole lot went back together, and as expected not a damn thing had changed - the fan still only works flat out. It would appear it is only getting power when the slider is at its maximum.
My next step will be to obtain a wiring diagram and check out what is happening at the multi-connector on the fan compared to what should be according to the diagram. Can anyone help with one for this car, please?

Thanks.
 
Turned out with mine that I was using the wrong fuse list. One of the fuses I removed to try to stop the locking problem was the fuse for the fan!
 
Take a look at the 4 pin connector to the fan - eventually the contacts lose some of their "spring" and no longer make contact except maybe when the slider is full on and the resistance to 12V is quite low. Get some very small screwdrivers and force them into the spring contacts and heavily push towards the middle of the connector. It should work after that!
John505
 
boodek said:
The latest installment with this saga happened today. I pulled the ignition switch/barrel to bits and it looked as good as new - no signs of overheating or melting anywhere at the barrel or any connectors downstream. I also pulled the ventilation controls out and stripped them down to have a look at the fan slider contacts. They were as clean as a whistle but were given a spray with contact cleaner and a wipe over with a clean cloth anyway before reassembly. The whole lot went back together, and as expected not a damn thing had changed - the fan still only works flat out. It would appear it is only getting power when the slider is at its maximum.
My next step will be to obtain a wiring diagram and check out what is happening at the multi-connector on the fan compared to what should be according to the diagram. Can anyone help with one for this car, please?

Thanks.
Click to expand...

Does your (new) or old "resistor pack" look like the attached?

If yes, carefully remove the little disc of metal under the arm "thingo" and clean both sides of the disc and the surface under the disc and the underside of the arm with wet and dry or fine emery and put it back together (again being careful not to put too much load on the arm). It fixed mine.

AND just to please me check that the battery connections are clean and tight.

Good luck. :)
 

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Why don't you take it to a decent auto elec?

My Mi16 fan stopped and it was traced to a faulty relay.
 
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