Weird Astra Electrical Fault

Hi
Hope you guys can help me out as you have been brilliant in the
past. I have a 1.4 16v 2000 Astra that has had a wierd problem since i
bought it secondhand. The issue is that the heater fan sometimes stops
working at all speeds then will randomly work fine for weeks at a time
then stop working again. Another thing i have noticed related to this
is on a recent long drive the rear window heater failed along with the
fan ie no light came on to indicate it was working and no relay
clicking could be heard. On turning off the ignition then turning it
back on again they both sprung into life and worked fine for the rest
of the journey. Are the two problems linked?
On a note there is no air conditioning.
I have checked all fuses and all appears fine there.
Can you advise where to start looking as i do not want to hand it to
the dealer and them take £50 to look at it and say "we cant find a
fault"!
Any clues/ideas what to check would be great as this is really
annoying and am unable to find anything related to the problem on the
web.
Is there some sort of circuit breaker which cuts in if there is a
fault or gets to hot?
Is this a known fault?

Any help would be great

Thank you in advance

Damian T

 

A lot of intermittent problems like this can be down to bad earth
connections.

Dave

 

relay going down?
fan stopping could be brush related also.

mike

 

Are the fan and r/w heater on the same fuse? Can you rig up a jury-rig
circuit whereby you can tell with the aid of a voltmeter or a 12v bulb at
which point in the circuitry there is no voltage when the system fails to
work? This rigup needs to be relatively exposed so that you are able to do
some testing while on a journey if necessary, without having to do any
dismantling at that time. It should be possible by trial and error to find
the 'bad' point. If there is no loss of voltage right up to the fan motor,
then it would seem to be a motor problem, but this is unlikely to be the
case if the r/w heater fails at the same time.

Rob Graham

 

Now for the daft suggestions - you could try replacing the fuse just in case
that is faulty - or swopping with a fuse for another part of the electrics
that work fine (and use the same fuse rating of course!) and see if the
problem "moves" ....

 

This is usually the fuse holder, it gets hot, distorts and disconnects.
Rewire an inline fuse holder in its place and all will be fine.

MrCheerful

 

Or you've got a corroded earth wire.

 

Having just had almost the same problem for a matter of months though with a
cavalier, I may be able to help, my problem was a bad earth running from the
bodywork to the engine.

My symptoms where cooling fan not working correctly, excessive engine
temperature, struggling to start (sounded like a lazy starter)

Hope this helps,
Dave Jones