Temperature gauge not working

Post by **deniro** » 08 Aug 2008, 20:11

My temperature guage has decided to stop working. Have checked the wiring by rubbing the spade connector against the engine block and the temp guage rises slowly, so I assume the wiring/earths/dashboard connector are all ok. I changed the temperature sensor as I guessed this wasn't working, but the gauge still doesn't move. I have a 1985 van fitted with a 1.9 1Y diesel engine. Any ideas what else it may be?

Post by **AngeloEvs** » 08 Aug 2008, 23:48

Sounds like an earth fault but don't the the diesels earth through the sender straight to the block?

Post by **deniro** » 09 Aug 2008, 08:59

Thanks for the reply

Don't really know as I am another mechanical know-nothing! I have a mechanic for anything technical, but he says that if the gauge works when I rub the connector against the engine it can't be the wiring at fault. The engine is running fine and the radiator fan goes off and on so can't see why the guage still doesn't work. I may go back to where I bought the sensor from and ask if it may be a faulty one, but that's unlikely (although possible).

Post by **Mocki** » 09 Aug 2008, 09:20

before you go back to get another sender ( Although it maybe the fault) run a temp wire from the sender to the gauge directly, see what happens, as it sounds like a cruddy connection maybe the reson..... increasing reistance and making the senders signal not enough to move the gauge.

chances are its the plug on the bottom of the dash, or the earth point behind the fuse box.

the rad fan will work regaurdless, it takes its control signal from the sender in the rad, and doesnt have a clue how hot the engine is, it dont even realise there is a engine, it cares not!

Post by **clartsonly** » 09 Aug 2008, 15:32

if you short it at the temp sender end and the gauge rises surely it must be the sender unit faulty?

Post by **AngeloEvs** » 09 Aug 2008, 15:40

Depends on the sender, if it has two connections then the other is the earth return path. Take the connector off, should have a brown wire, check it goes to earth. If it has one conx, sender earths to engine block. You shouldn't short the gauge to earth for anything more than a few seconds. The shunt inside and the stabilser will overheat.

Post by **clartsonly** » 09 Aug 2008, 15:43

do the diesels not have the same plastic thermostat housings ar ethe petrol meaning that they have two connectors one to earth.

Post by **AngeloEvs** » 09 Aug 2008, 15:46

Dunno Clarts, I asked him that. Pretty sure it will have tho!

Post by **deniro** » 09 Aug 2008, 17:48

Hi All

Thanks for all the replies and advice, seem to have started a bit of a debate here! After reading what AngeloEvs said about the sender earthing straight from the block I managed to solve the problem. When my mechanic changed the sender he said it should have a washer to help prevent damage when tightening it up. As there was no washer there he found another one and used that. The gauge still didn't work but after reading AngeloEvs message I connected a wire directly between the sender and the engine block and the gauge went straight up to the middle

. The washer was the problem! Removing the washer solved it. All sorted now, thanks for all the help from everyone who replied.