SLROC Forum

Hi All ,
I have a 1979 series 3 which has a Perkins diesel BB50401 engine fitted , the temperature gauge does not work and the previous owner confirmed that it did work when he had it  .
I’ve checked the gauge by taking power to it and it rose slowly .
Looking at the engine I can see what I think is the sender switch on the right side ( looking from front ) towards the rear , there are two wires coming from it that I can trace to the thermostat housing . What I can’t see is where a wire would feed the gauge .There is the possibility that the previous owner is mistaken and the gauge has never worked and if so would it be a case of taking a spur from the sender straight to the gauge .
The previous keeper is genuine and a very nice man so I have no reason to doubt him.
Thanks
Donald

There should only be one wire from the sender.
If you use a meter you can measure the cold resistance and then warm up the engine and you should see a different (lower) resistance when hot.

                          Pete.

If you earth the wire on the sender out on the block the gauge should rise ,if not you have a wiring / gauge fault

There should only be one wire from the sender.
If you use a meter you can measure the cold resistance and then warm up the engine and you should see a different (lower) resistance when hot.

                          Pete.

Hi , on the Perkins engine there are two that go to the thermostat housing , I read that possibility the fuel mix alters from cold to hot but not sure ..... I’ve just found the original green/blue wire that should go to the sender , again I read that someone with this issue fitted the sender from the original engine ( which I have ) into the hose that goes to the thermostat, copper pipe with a manufactured part that will accepted the original sender .

If you earth the wire on the sender out on the block the gauge should rise ,if not you have a wiring / gauge fault

Hi , yes I did that and the gauge worked fine , see my other reply , I think I need to use the original sender and try and fit it somehow.

I’ve worked out that the Perkins engine has a completely different temperature reading set up to the original Landrover petrol engine , I have removed the temperature sender from the spare original engine and I’m going to try and fit it to the top radiator hose near the engine thermostat housing , this will give me a reading that might not be spot on but close enough and would definitely warn of any overheating should that ever occur .
Will update when done .

Temp gauge working now

  Yeah I love a happy ending!

            Pete.

Note for the future.  If you find temperature readings erratic, this could be because of air in the hose. To solve this simply turn the sensor to the side  or upside down to ensure immersion.