For some reason the temperature guage on the defender has decided it wants to do more than show just the temperature, it also wants to show the revs as well.
when you rev the engine with the handbrake off either in or out of gear the temperature guage drops to cold, and then when the engine is allowed to idle it goes back to normal, however if the handbrake is on it doesnt do it everything else electrical works fine its just that.
I went to the local stealership and they wanted the best part of £100 just to do a diagnostic.
So has anyone any ideas?

One thought - have you checked the earth connection to the block from the battery/chassis? Sounds like some sort of mechanical influence is causing a circuit to vary, the earth is always a good start.

Other than that, get someone to operate the handrake and see if any cables are moving/flexing due to being mis-routed.

HTH

Mitchell

As John Points out it sounds like an earth problem, have you fitted anything new to it at all, or has the problem just started on it's own?

Regards

mark

Hmmmm funnily enough i have fitted a new stereo in it, although it was alright for about a week then it went.

Trace back to all the connections you made when fitting your stereo, and check them against a wiring diagram - also check you didn't accidentally disconnect something when you was wiring up the stereo - sounds like that may be your problem.

Regards

Mark

Right, spent the best part of the day buggering about with various earths on the defender, with absolutely no result whatsoever, however i have discovered that if i run a cable from the hand brake mounting bracket to either the chassis or the transfer box it stops doing it.

Does this mean that the earth from the body to the chassis is causing the problem?

I also checked the stereo and is fine, i also checked for a possible short within the instrument panel, and didn't find anything.

If it is the earth from the body to the chassis do they break or need replacing as i had it off earlier and cleaned the ends up.

not sure mate, if it's not something you've done when fitting your radio then I don't know what it is sorry - sounds like John was closer to the problem though, perhaps he will be able to tell you more?

you can check there is no resistance through the earths if you have a multi-meter?

Just had a thought - don't know much about the electrics on the later Defenders but if they went the same way as most modern cars it might be worht checking all your fuses to make sure none are blown, as they sometimes share earths, is an easy check while your waiting for more advice anyways.

When you say the h'brake mounting bracket, I guess you mean where the lever mounts on the seatbox? In that case, it does sound as though the body is not effectively earthed to the chassis.

You say you took the body-to-chassis earth lead off and cleaned the ends, did you make sure they were nice and bright with a wire brush or emery paper or similar, also that where they make contact under the bolts is similarly clean? A good tip is to use vaseline on the area while reassembling, to help to keep water out. The lead should not normally need renewing, although if it has crimped-on ends I suppose there could be corrosion inside - a good tug on it should reveal if the wire is no longer connected inside.

If in doubt a new lead might be a good idea, I can't imagine they're very expensive.

Good luck!

John

Thank you everyone who has given me advice. It is the earth from the body to the chassis, that is causing the problem.

Cheers mitch.