Magnetic Dash? - Compass Deviation

[OZ Landy]

Defender 130 TD5 2001

Hi Guys

I have got a strange problem.
I fitted my old trusted magnetic compass to the front of the dash board (just left of the steering wheel) and encontered a strong magnetic field.
The compass sits on SW all the time.
I have removed the stereo, the speakers, and the complete dash: no change.
I checked with another compass, still the same. the compass work well in a other car.
The metal structure behind the dash seems to be stongly magnetic for some reason. Any bright ideas how to get rid of that because I'd very much want to use that old-fashioned compass.

Cheers

[Sprint]

remember, the firewall is all steel......

[Sleepy]

I gave up with trying to find a reasonable place for my compass in my Td5 Def.

I put it down to the electronics.

Works fine in the Series 3 which probably has just as much steel.:mad:

[JDNSW]

It is a bit much to expect a magnetic compass in any vehicle - you are operating in close proximity to a couple of tonnes of metal, mostly ferrous. The best location would be near the top of the windscreen, but even there vehicle influences will be significant. You may in fact do better with a vehicle that has an all steel body, as the magnetic influence is much more uniformly distributed, where with the Defender, the magnetic bulkhead is not counterbalanced or corrected by steel bodywork in other directions.

John

[Reads90]

Hi
I bought a boat/ Car compass made by Silva . It is designed to cope with firewalls and large lumps of metal in front of it ( ie the engine) They have an adjustment on them

This is the one i have on the dash of my 90 ( in the middle above the radio) and works fine

http://shop.packyourbags.com/acatalog/t_compass_adv58star.jpg

[OZ Landy]

I agree it has to be a magnetised firewall as John explained so well.
Has anyone ever attempted to demagnetise it?
I used to do it with TV screens but the tools for it are far too small for a firewall.
Cheers

[lambrover]

I think the wiring would create more magnetic influence than the bulkhead. When current flows through wires it creates magnitism, there are a lot of wires behind the dash.

[Sleepy]

Yeah, mine works fine with the ignition off.:angel:

[lambrover]

Yeah, mine works fine with the ignition off.:angel:

well that conferms the diagnosis, do you remember science class or experimants were you make a magnet with a coil of wire and a battery.

[Sleepy]

Well not sure that confirms it. Reads90 obvioulsy has his working ok. :confused:Mine is a similar SILVA (older model) I had it swung properley compensating for the deviation of the steel/alloy but defintely effected by the ecu/electrics. As I mentioned it works fine in the Series 3 (virtually the same mass of metal but a hell of a lot less electrics.)
What type of compass is it?

In the end I went with a good GPS and a external antenna. I like having a compass for maintaining situtional awareness, but in the end the GPS has been great - I usually just leave it on the compass setting:angel: