Series 3 Fuel and temerature guage question

Hello
Often bother dials of fuel and temperature gauge in my truck are fallen at the lowest position.
They always either both are OK or both are not working at the same time.
It is not because of a fuse I have checked that. Also the the red light right bellow in the middle is frequently on.
Any idea what causes this?

I would say a poor earth is the cause of the guages not responding properly. When you say, red light, do you mean the ignition light that should go off when the engine is running?

Col

Poor contacts in the fuse box often the problem, next time they are down spin fuse in holder and see if they work.

Colthebrummie said:

When you say, red light, do you mean the ignition light that should go off when the engine is running?

Click to expand...

the red light in this picture right in the lower center bellow the word CHARGE is practically on all the time.
Also, to avoid having to see another mechanic: Where is the ground that goes into that panel?
thanks in advance

The charge light comes on when the Dynamo or alternator isn't supplying enough power to the battery. The light might be staying on for a number or reasons, a bad alternator/Dynamo or a bad contact somewhere. The light staying on and the faulty gauges are probably related, if so it will be a wiring issue probably behind the dash.

Col

Also, if it's an alternator, check the plug connection that fits into the back of it. I would also use a multimeter to check what voltage the battery is when it's switched off and compare that to when the engine is running. If the alternator is supplying power, the second reading will be higher.

Col

The earths are often fixed to the thumb nuts that hold the gauges on, all strung together then onto the bulkhead. its all gets loose and dirty.

Thanks for the replies guys.
I used my multi meter to read the battery with the engine on and off and it showed 35 volts in both cases! I have to find a proper multi meter first.

I opened the panel cluster and moved it out (as far as steering wheel permits) to see the jungle of wires behind it. I can not find any grounds although to be honest I dropped a screw and in that mess I could not find the damned screw again either.
Where are these thumb nuts supposed to be. The three screws holding the combination panel in my truck are going to plastic frame that surrounds the square combination thing (so that cant be what you mean).
On the positive side I noticed moving and shaking the thing as it is attached to the bunch of wires make the gauges come to life. Which wire I have no idea.

35 volts. Was the meter set to DC? The trouble with old series landies is that half a dozen previous owners have probably been behind that dash panel before you and have done all sorts of alterations and bodges. You may be better off establishing your own good earth and connecting the guages to that. Does the 2 pin power socket work?

Col

Also, when mucking about with wiring, a wiring diagram is a must.

Col

the thumb nuts mentioned can bee seen in 2nd pic of this advert round nuts.
https://www.ebay.co.uk/itm/Land-Rov...345451?hash=item4209bedf2b:g:dE0AAOSwWq9dlN27

Thank you guys.