car almost sets alight

[TehAgent]

woot my first 406 problem, but it almost set the car alight lol.

needing some help, passenger side foot well behind the glove box sits the heater fan, this morning on the way to northampton the heater and subsequently the climate control display stopped working, after a lot of smoke and the smell of burning subsided i limped the car home in the cold.

only to get behind the glove box to notice that a wire had burnt through.

after checking fuses and none are blown that i can see anyway, im wondering what kind of damage has been done and how to go about sorting it out, attached are some piccys of said wire.





from what i can tell the red and black wire run to the fan, the green and gray wire i haven't a clue about, but bit annoying when its winter an i have no heat and no way of clearing the windscreen of ice in the morning.

any help would be much appreciated as i have to drive my 8 month old baby around in the thing.

EDIT: please note when the photos were taken the green and gray wires casing had fallen away due to me trying to unclip them.

[CitroJim]

Hi Ian,

That's the supply to the blower speed controller by the looks of it and I reckon the same has happened there as does in the Xantia; it started out as bad connections that overheated and then melted.

You'll not find fuses for it in the passenger compartment fusebox but there may be in the engine compartment but even then, maybe not as the blower supply comes directly from the ignition switch. Look at the wiring there and you may find more damage there. You may even find part of the ignition switch has waved goodbye as it does in the Xantia.

Re-wire, make good and do the Xantia blower relay mod (see the sticky in the Citroen forum) and all should then be OK, hopefully.

How's Tess and little 'un? Is she really 8 months old now

[AndersDK]

Tx submitting the pictures.
Really "nice" example of a dodgy burn out in the wiring

Agree with Jim.

Fuse F20 protects this circuit, so hopefully it has fused.
But only if the blower has been on full pace.
Otherwise you may have a burnt out speed setting resistor pack, which now only works on full setting.
The ignition switch will not be harmed.

You may get away with cutting back the red/black wires until they separate again.
Then simply use a new set of standard crimp connectors. Preferably the round/pegged type.

Note : use FEMALE connectors on the red/black wires to avoid earth contact on the positive terminal.

[TehAgent]

Tx submitting the pictures.
Really "nice" example of a dodgy burn out in the wiring

Agree with Jim.

Fuse F20 protects this circuit, so hopefully it has fused.
But only if the blower has been on full pace.
Otherwise you may have a burnt out speed setting resistor pack, which now only works on full setting.
The ignition switch will not be harmed.

You may get away with cutting back the red/black wires until they separate again.
Then simply use a new set of standard crimp connectors. Preferably the round/pegged type.

Note : use FEMALE connectors on the red/black wires to avoid earth contact on the positive terminal.

Bugger, i have the electronic climate controls, so it comes on at low speed automatically...

had a look in the normal fuse box in the car, no fuses blown from what i can tell as all the backs are visible, had a look in the fuse box under the hood and from what i can see no blown fuses there either =(

Ive cut the wires out of the car as the damage to the connector was just too great and its welded the two halves together, i cant figure out what color wire goes to what, is it red to gray or red to green? I'm thinking its red to gray as the green look very much like an earth wire.

From the looks of it, it was arc-ing, inside the connector, heated up the wires to the point the plastic coating spontaneously combusted. it got that hot its melted and fused the copper wire together. so i couldn't figure out what wire went to what.

Typical this happens a week after the misses says she loves the reliability of it lol, i did tell her that considering we haven't had anything go wrong that it would be a major thing when it did

And yes Jim keira is now 8 months, said her first words the other week, dadda and mum mum, then didn't shut up saying them for about 3 days, now she just oo's and arr's

[citronut]

if there are any fuses poped you need to pull them out to check if they are gone, and its likely to be a green one =( 30 amp )
regards malcolm

[TehAgent]

Good news is i found the blown fuse, it was in the engine bay, but it was one of the big 50 amp ones, i had a blown fuse in the cabin as well but it was only fuse a1 and only 10amps, (not even sure what fuse that belongs to lol)

I'm hoping that all that needs doing is the cables rejoining and the fuse replacing.

Can anyone help me with what color wire goes to what, the male end of the connector (see photo) the wires running into it are red and black, on the female end of the connector the wires coming from it are green / yellow (earth) and gray.

Really don't want to be wiring it up wrong.

[AndersDK]

I must admit I got it all wrong in my first post
I was thinking Xantia which explains the weird fuse no ref

Back to realities though :
Clearly the red & black wires are the blower fan feeds, and also its quite clear from your pics that the fan is controlled by some electronics, by the looks of anumber of small gauge wires also leading to the blower motor.

Since the wires leading IN to the unit has fused well and truly, I dont expect the motor and power controller unit itself to be defective.
This leaves us with only one problem : how do we connect the wires upon cleaning up and new connectors fitted ?

The use of a red and a black wire on the fan blower unit suspiciously depicts the standard usage of red for the +12V feed and the black for chassis earth.
This is the most common used standard by makers of automobile electric units. Also these wires have nothing to do with the legacy Peugeot wiring harness.
I therefore believe its safe to assume the red wire is +12V feed to the blower unit and the black one is chassis earth.

Its a lot easier checking the grey & green wires, as they simply feeds the +12V fused supply and chassis earth.
Using a standard automobile testlamp (those cheapo types with a needle tip and wire terminated in a crocodile clip) its then very easy determining which wire is the chassis earth :

Have ignition on (position : drive) Conncet crocodile clip to battery plus terminal and try both wires. The one that lights up the lamp will be earth, and should then connect to the black wire.

Now move the crocodile clip to battery minus pole and try the remaining wire. It should readily light up the lamp telling you have found the +12V fused feed.
To doublecheck : remove the 50A fuse and observe the testlamp extinguishes
This wire then connects to the red wire.

Job done
Enjoy the work ...

[TehAgent]

I was thinking more along the lines of; wire them up how i think they go, if the car sets alight, have a BBQ, take a few photos for the forum, claim on insurance and get a new car lol

Either that, or be right the first time and i have my blower motor and heat back.

[Decca]

Has anyone been fiddling with the wiring to the heater, prior to the fireworks?


Please advise if I am wrong as the following ramblings assume what I percieve from the pictures.

top picture appears to have the red wire connected to the green yellow wire (generally indicates earth )
Second picture shows same wire colour earthed to bulkhead. Even confirmed by haynes book of wonders as a double earth connection.
(Other earth wire goes to heater panel)

Methinks someone connected wires back to front.
This means the blower control module was powered incorrectly. being an electronic device it may be toast. but you could be lucky.
I say that because a shorted module would probably have melted the red and black wires all the way to the fan assembly, instead its melted only at the connecter, which as mentioned by others indicates a poor connection which could have overheated due to the voltage drop over a high resistance joint.

So... according to haynes manual..Fuse 2 (50A) feeds the blower control module via ignition switch (hope switch ok after 50plus amps flowing through it), and the module feeds the fan motor.
Fuse 2 also feeds fuse 21 (10A) which feeds heater panel.

I would check insulation is ok over the whole length of the red and black wires, reterminate wires, connect red to grey, and black to earth.

Put in 50A fuse turn on ignition and hope for the best. Or maybe, first remove brown connecter on fan assembly and fuse should hold as fan assembly is isolated. turn off ign then try again after plugging in fan ass connecter

Getting late here, hope all this makes sense. Good Luck!

Decca

[TehAgent]

the pictures are misleading, after careful examination of the cut off wire (the melted part) red went to gray and black to green/yellow. haven't had a chance to get a new fuse but have done some testing using the 50A fuse for the from lights / high beam.

connected the red to gray and the black to green, turned on the ignition, and got my display back and the fan kicked in, started the engine and got heat after 5 mins, tested all the settings, rechecked the glove box fuses, tested the rear screen heater, everything works as it should.

For once a fuse did what it was designed to do, and that's blow before any harm can come of it.

just need to reconnect the wires properly now (using electrical tape with a bit of wood in between the wires to stop them getting near each other). as a temporary measure at the moment, all i need to do is replace the 50A fuse yay.

[Decca]

That's good. Glad it was an easy fix, and no parts needed.

Seems to be a problem over there as there are quite a few threads on fan/heater problems. Don't believe we have as much trouble with them down under


Decca