another electrical query

[ubertub]

'lecky advice needed:
every now and then my clocks don't work.... well, most of them. The petrol gauge, rev counter and speedo don't work. The oil level and pressure half works and the battery warning light comes on faintly. If I press the brake pedal the battery light glows brighter and the rev counter works a bit. Also the heater fan does not work.
Then, inexplicably, the whole dash lights up as on start-up and everything begins to work as it should, and the battery light goes out.
9M have replaced the ignition barrel which made a difference for a short time, but I think this was a coincidence as the problem has returned. They swapped all sorts of bits and bobs on and off again but were unable to find the cause and the problem remains.
Could it be a loose connection with the fuse box? Are there any components which are common to the clocks and heater and brake pedal switch?
Deep joy.

 

[Graham-S]

Sounds like your having a nightmare!
I don't know how electrical you are so I'll ask the questions and see what you say. Does the car start ok every time, and as easily as it should?
Do you have 12v at any of the gauges that don't work? Have you tried putting a ground (Earth -) wire straight from the battery to the ground on the gauges? It could be a bad earth?
Does any of the gauges work when driving (eg over bumps etc?)
Have to start somewhere!

Graham

 

[ubertub]

thanks 'tel.
Unfortunately I am not electrically minded at all... I think it's witchcraft to be honest!
Going over bumps does sometimes seem to coincide with the heater fan and dials coming back on, but not every time. The engine starts first time, every time and runs perfectly.
Oops! Just remembered I have not put the bonnet seal back on... could it be water ingress into the fuse box which evaporates once the car has been driven for a short time. It is usually about 20mins before things start working if a bump doesn't do the trick.
I have not tried to do anything with the earth/ground to the clocks as I have no grasp of how electricity works and will probably end up setting fire to the poor car.
Is it time I went to an auto-electrician?
ta.
mik.

 

[Graham-S]

Well that seems to rule the altanator as it starts everytime ok
Have you had any work done to the car eg, Body Work, Radio, Car Kit, Service etc?
Put the bonnet seal and have a look round the fuse box are local area to see if you can see evidence of water.

Graham