Heater fanswitch

[Lennart Sorth]

A long time ago, I joked with Will Falconer (MatraMagic) that my Murena had a fanswitch with 3 positions: 50%, 60% and 70%, and I think he suggested that maybe mine was "tired", and it would help to replace it.

anyway, I bought one, - but then simply forgot all about it (bad boy!) , until I was brutally reminded the other day...

I was sitting in a traffic queue, with the fan on "1"  as ever, which creates lets say "minimal" air-circulation, so the air in the cabin wasn't moving a lot (except along the windshield)

The sun was hammering in through the window, and it was now apparent that something in my dashboard was emitting smoke (!) - it was running along the underside of the "canopy" and was sent upwards at the far right, looking like a nice Apache smoke-signaling post...

I quickly turned my attention to the heaterfan switch, which evidently was hot to the touch (behind the knob).  I turned the fan off, which eventually stopped the smoke (phew!) - and I continued home, now recalling that the new unit would have to be somewhere in the piles of parts (=junk) in my workshop.

Amazingly, I found the switch within only 15 minutes of searching, and set about replacing it - hoping that this was indeed the cause.

As soon as I had the old one in the open, it was blatently obvious that I had found the epicenter of the smoke emission - as the plastic around the cable-shoes (terminals?) were severely melted.  see the attached picture.  I don't know if the rusty appearance of the one connector is the cause, or has become like that because of the heat.

It seems likely though that it was the cause, as that probably made poor connection, which causes a voltagedrop, and with the amount of current needed for the fan, this would produce excess heat at the connector. The rust can originate from the long-gone days when my car had a leaky sunroof, and as such has had its damp experiences.

Anyway, I replaced the switch and fitted new cable-shoes - and actually I think the fan sounds like it has slightly more oumph - like 55% 65% and 80% :-)

I took some educational shots while doing this - which are all here:
    http://www.matrasport.dk/Cars/Murena/Stories/fanswitch/index.html

This goes to show how much one should be aware that quite a lot of amps are traveling around our beloved cars's wiring loom, and every bad connection is a potential firehazard, as well as lowering the voltage and causing other problems.

For now, - hopefully, no more smoke!

[Anders Dinsen]

I took some educational shots while doing this - which are all here:
    http://www.matrasport.dk/Cars/Murena/Stories/fanswitch/index.html

Excellent, thanks for that instruction video - blrrrr pictures. Very good indeed.
If you open the old switch you will probably be able to determine whether the problem was the connections to the switch or the switch itself, but from the picture I think there's little doubt that it was the terminals that were simply not tight enough, and probably had welded together at one point, but then after being torn apart had simply started rusting away. Moisture could also have played a factor in degrading the connection.

This reminds me that I should take a look at the terminals going to my ignition lock.... I think they have the same look.

- Anders

[Matra_Hans]

Hi
I experienced the same problem a couple of years ago: Smoke and smell of burning wires in the cabin instead of the fan blowing air.
I reused the original switch, just replaced the wires and made some proper connections.
It has been working ever since.

Hans

[Lennart Sorth]

Hans, - interesting to hear that you also had the same problem, - I think a good recommandation to all Murena (and all older model) -owners, is to check all connectors - especially those carrying any amps.

I did take the switch apart, and it was quite obviously a connector problem. The switch itself is worn, but looks to be in reasonably good shape. I have added a picture on the gallery.

Actually I wasn't aware that is is in fact a simple switch, - no resistors or anything, but it does make sense that those are in fact integrated in the fan-motor  itself, probably in a way that sends a little airflow around them, to keep them cool (?).

Only one of the connectors on my old one is quite damaged, but it can be cleaned enough to make up a spare, in case the new one should fail completely, so I will add it to the piles of rubbish in my workshop.  (this is how it piles up) :-)

/Lennart

[Anders Dinsen]

Only one of the connectors on my old one is quite damaged, but it can be cleaned enough to make up a spare, in case the new one should fail completely, so I will add it to the piles of rubbish in my workshop.  (this is how it piles up) :-)

I never throw anything away; I might need it one day!!

A bit of cleaning and/or filing on the spade would probably make it as good as new. Same goes for the inside of it...

[Anders Dinsen]

This reminds me that I should take a look at the terminals going to my ignition lock.... I think they have the same look.

hmm... it looked like a fire had happened there a while back... I'd better keep a good eye on this - it's certainly scheduled for a proper repair. For now, I've just wound some tape around this.

[Anders Dinsen]

Had to move my car from where it was parked, so I took a spin around the block, 5 minutes on ignition, and the wires were quite hot! It's more serious than I thought... have to fix it tomorrow.

[Anders Dinsen]

Had to move my car from where it was parked, so I took a spin around the block, 5 minutes on ignition, and the wires were quite hot! It's more serious than I thought... have to fix it tomorrow.

So I did (as Lennart can witness) - what a job, soldering wires under the dash!! Anyway, it turned out the heat had melted the insulation right up to the lock itself. That was pretty serious as I couldn't just cut the wires a bit down. Ideal solution would have been to crimp entirely new wires on the lock - or replace the lock entirely. Neither was possible on a Sunday, instead I cut the wires only 2 cm from the lock, pulled the insulation off, soldered new wires on, and insulated the soldering and the piece of the old wires still in place with shrink tubing.

That was easy, as it could be done in my workshop - next part was more difficult as I had to cut the wires sitting in the main wire harness quite far up under the dash (again because of melted insulation) but with the radio removed I managed to solder it properly and finish it off using shrink tubing.

A quick test showed that it was not getting hot, a 30 minute drive this morning proved that.

The problem was obviously one or more of the connectors between the lock and car cabling which had developed a bad connection and was heating tremendously. Copper transfers the heat quite well, therefore it had melted all the way up to the lock.

Volt meter sits better now (though it still can't be trusted, see my other thread!) and ignition seems to work better too on the engine!

[macaroni]

Sounds nasty, do you think all of us Murena owners will have this problem to a greater or lesser extent?
My ignition switch is fine, but I did have the alternaator wiring redone.

[Anders Dinsen]

Sounds nasty, do you think all of us Murena owners will have this problem to a greater or lesser extent?
My ignition switch is fine, but I did have the alternaator wiring redone.

Yes, I think all Murena owners will have problems with connections between power carrying wires - but I think there are more common places for this to happen, e.g. the spade connectors on the wire from the battery to fuse board. Normally, though, the connectors fuse together when the connection becomes loose, which cures the problem - only if they are then pulled apart with force and together again without cleaning will it start to get really bad, I think. That must have been what happened with mine.

Whether the wiring to the ignition lock is a common problem, I don't know...

[Lennart Sorth]

do you think all of us Murena owners will have this problem to a greater or lesser extent?

Yes, I am pretty sure we all have thse potential problems.

I have just had a good look at my fuseboard, and found poor connection on most of the relays, - cleaned them, and tightened the flimsy sockets, which brought back good contact, and: headlights! - wheee :-)
(well, they weren't completely gone, but twice in the last week, they didn't come on, until I had massaged the relay manually)

I also found that the print "lane" under the connector which supplys power to the extra headlamps (fog lamps) was highly deteriorated - actually so much that it fell apart when I pulled the connector off !

I use those lamps as daytime driving lights, so I am constantly pulling power through this, which it maybe wasn't really designed for.

I replaced it with a thin sheet of copper, which I wound around the board end, and glued it on both sides, before soldering it to the circuit. (of course no glue to the contact side)
This way the contact is actually using both sides of the connector.

Actually, if your fuseboard is otherwise in good shape, this could be a great improvement, - simply wrap copper around the print for each print "lane", - superglue it, and solder.

However, I think I subscribe to the double-sided fiberglass fuseboard replacement - either homemade, or maybe simpler one from Politecnic/MatraMagic.

/Lennart

[Anders Dinsen]

here's a couple of interesting pictures for those of you who want to see burnt wires 
and the fix

[krede]

Driving along today, I decided to treat myself to a little cold air as it quickly gets pretty hot in the small cabin... even if the temperature outside isn't high.
As it is rather windy today, i decided to leave my windows closed, and give the cabin fan a go. (I usually just roll both windows slightly down, as this gives much better ventilation then the fan will ever manage)

Turned the nob to position "3" (witch you really need if you want just the slightest breeze).. and Ahhhh.. a little fresh air..

After a minute or so of cross town driving, I noticed a "flower" like smell..from what i believed to be outside...  thinking "ahh how nice"... well... Nice .. sure... Until smoke began POURING out of from the center of my dashboard!!!

Luckely for me it stopped (a while) after I turned off the fan.....(its still working)
Had it decided to catch fire, It could have turned very bad, as you can not easily get to it behind the dash... (especially not without any tools)
And Im now sure attempting to "blow out" a dashboard fire , through the heat regulator slits is the way to go about it..

Moral : I highly recommend having some kind of fire extinguiser in the car... doesnt have to be a 5kg unit.. .. but I got to feel, just how helpless you are without ANY means of putting even the smallest of fires out... and lets face it..... electrics HAS been known to go wrong in these cars.... though of cause not "peugeot 307" wrong
 

[Anders Dinsen]

Hi Krede

I LOL'ed reading your post, wonderful story
Life is a learning process, they say. I rushed out to buy my first fire extinguisher after parking my '87 Espace when the high pressure servo hose had started leaking oil onto the exhaust manifold. Fortunately the oil didn't catch fire, but it smoked a good deal! 

- Anders

[davidewanprice]

These pictures really make you think, I looked under my dash a while back and noticed the amount of wires that had been added over the years,  many just seemed to go nowhere, it was scary! Afterwards id wires left over that had been added to the originals for god knows what reason and for the first time my entire dash was fully lit up and my clock worked! I also noticed some of the white connectors looked melted just like in these pictures. Future project there i think.....

Also i noticed in the DIY destruction of the fan switch pictures that their rear screen heater bulb has melted the cover, mine too, has everyones done this? Is there a way of using LED's instead, producing light but not the heat?