406 HDI 110 - Hot key

This concerns the ignition key (which on a diesel it patently isn't) for my
S reg 406 HDI 110 which is, as Nigel and others will remember, a hybrid
being mainly a Mk 2 mechanically and mainly MK 1 bodily.

This may have always been the case but I have only recently noticed it or...

A week or so ago, I pulled the key out after a round trip of about two
hundred miles and noticed that the blade was very hot. I have checked it
since and, even after a short trip of half an hour, it is very hot. Is it
something that always happens, but I have not noticed before, or is it
indicative of a problem? Any thoughts gratefully received.

 

Keith Willcocks wrote:

..

Sniff the lock, are there any burning smells? I'm not the world expert on
cars but this definitely seems wrong to me.

 

I had the same car, S Reg 406 and the key was always hot,
it ran like that for couple of years till I swapped it for
02 estate. The present owner still has a hot key, but it
doesn't seem to cause any problems.

Bryan

 

Give your main Dealer a ring about this matter.or ring a auot ele man ,
if you got anybody round near you with the same car ask them.
good luck please let the group know what the out come is.

 

It may be due to the fact that it takes a large load through the
ignition switch part. I seem to recall the heater blower motor feed
goes through it at least. May account for the heat. I'll try to
remember at work to check the keys after a road test!

 

Zoab wrote:

Odd, is there something putting out a lot of heat in that area,
are the switch contacts dirty or is the switch overloaded. Given that the
contact resistance in the switch should be rather low it should take an
awful lot of current (too much) to make it even warm.

Pete

 

Thanks Nigel. That would certainly make sense as over the last few weeks
the blower has been running continuously to push out cold air. My wife
says that she thinks her S reg 306 key gets hot as well so she is going to
check it. I will be interested to see what you find.

 

Good thought Pete, have a look at Nigel's reply which seems to indicate that
that may well be the answer.

 

Do you have TPFT or Fully comp insurance? If so don't worry unduly.

 

Keith Willcocks wrote:

Not convinced. Trouble is I can't see anyone listing typical ignition
switch contact resistances on line and I can only guess as the current
drawn by the blower. Power dissapated is I^2R. I just can't see anyone
sufficient load being put through the ingition switch to cause it to get
hot.

Pete

 

The more I think about it, the more I have a feeling that I noticed the same
thing last year - of course that could also be age related (me, not the car)
;o)

I will hang on and see what findings Nigel and my wife (when she remembers
to check) come up with.

 

Keith
Checked my key today (2.0l 16V petrol 406) after a 15 minute drive and it
was very hot, barely comfortable to hold.
Martin

 

That is exactly how mine is. I am thinking that Nigel's suggestion, that
it is the current being pulled through by the blower that is causing it, is
on the button as I went for about a thirty minute drive yesterday,
deliberately leaving the blower off, and the key remained cold.

It will be interesting to see if anyone else can reproduce the hot key
effect.

 

I did 2 406's today, both around your age (the car I mean!!). One
journey with the blower off of around 15 minutes. Key cold. The other
one on the same route with the blower on full blast and the key was
very hot. To be scientific though it would mean doing the two journeys
in the same car, but I don't think the customers would agree with
that!!

 

To be scientific, yes. But what you have found is good enough for me,
especially as two other people have come up with similar results. Once
again you have helped me out and put my mind at rest.
My sincere thanks Nigel.