light burning smell coming from heater

[staggc]

Lads,

getting a light burning smell out of the air vents when the heater is on.

Any ideas what up?

[addo]

Usually it's the blower fan motor, either the controller circuit board warming up excessively or the brushes arcing due to wear/loss of spring pressure.

[mrbritse]

Check this link out, that smell could be the coolant evaporating off too.
http://www.berlingoforum.co.uk/showthread.php?tid=359

[staggc]

Matrix replacement sounds like a big job. would it be worth having a look at addo idea first?

[ffrenchie]

Coolant leaking and evaporating usually smells like curry, well it does to me

[addo]

When my Xantia's current matrix was brand new it gave off a light burning smell, I'd scrubbed the heater box out so there was no coolant residue.

[mrbritse]

I think addo is probably more knowledgeable than I am so yes I would try his thing first. I just wanted to draw your attention to that possibility. I had that (curry?) smell for a while but decided to ignore it and see what happened, either it has now gone or I dont notice it any more. I seem to remember my old xsara had it too now and then. If it is a real electrical burning smell I think addo is probably right.

[addo]

I wouldn't so much say knowledge; it's more about burned/bruised/scraped fingertips from poking and prodding things that make me curious! :whistle:

My Xantia's blower control module fritzed out several times, in the end I determined the brushes were half worn away - you'd think it should still work fine, but in reality it was lacking the spring pressure to transmit enough current consistently - so it would slow, then the controller module would say "more speed" and it would speed up again with resultant slight arcing and ionising smell. The fast/slow muddle overheated the controller and scorched its circuit board, causing the tracks to become unbonded from its base material.

See how it goes for smell, with the fan speed set to a constant speed rather than automatic climatisation. If the burning smell can be mitigated this way, I suggest re-brushing your motor (about ten squid and an afternoon for the halfway handy). Brushes are likely to have been 22mm long when new - less than ten mil left and they're going to be problematic from my observations.

Re the matrix - try Forté before ripping the dash out.

[staggc]

would any one have a diagram for this / work instruction .Ill replace the bushing first and see if the smell goes

[pitpan]

I wouldn't so much say knowledge; it's more about burned/bruised/scraped fingertips from poking and prodding things that make me curious! :whistle:

My Xantia's blower control module fritzed out several times, in the end I determined the brushes were half worn away - you'd think it should still work fine, but in reality it was lacking the spring pressure to transmit enough current consistently - so it would slow, then the controller module would say "more speed" and it would speed up again with resultant slight arcing and ionising smell. The fast/slow muddle overheated the controller and scorched its circuit board, causing the tracks to become unbonded from its base material.

See how it goes for smell, with the fan speed set to a constant speed rather than automatic climatisation. If the burning smell can be mitigated this way, I suggest re-brushing your motor (about ten squid and an afternoon for the halfway handy). Brushes are likely to have been 22mm long when new - less than ten mil left and they're going to be problematic from my observations.

Re the matrix - try Forté before ripping the dash out.

What's Forte and what does it do. As I have the sweet smell of coolant evaporting when the heater is on