No temp gauge reading? Out of ideas

[MickeTJ]

I can´t understand this..
Please help me figure it out.

When I bought my bus, I noticed on the way back home that there was no temp reading.
The LED flashes when I start it up.
I decided to change the temp sender, only 15 €. (bought it at a general carpart store) said Opel (vauxhaul) / Seat on it but it looked exactly the same as the old one. (1 pin sender)

Nothing happened.

Next I tried to disconnect the wire from the sender and put it against ground.
The LED flashed but no movement on the sender.

Tried this test: http://www.thesamba.com/vw/forum/viewtopic.php?t=464113" onclick="window.open(this.href);return false;
with Resistors.

Nothing happened, no movement.

At this point i decided that the gauge was bad.

ordered a new one from vw heritage for a hefty 80€. Happy as a kid i ran out to install it today... but guess.. the LED flashes but nothing happened with the gauge movement?????

What els could be wrong??

[Bulldog1]

I would only use genuine parts from Brickwerks etc.
Try ordering the correct sender and check all wiring.
My camper had exactly the same issues and I bought a sender from just kampers and it still didn't work!!!!
I ordered another one from Brickwerks and sure enough I've now got a working temp gauge.

Good luck

[AdrianC]

Step back a bit from it, and be logical about it.

You have three basic components involved.
- The sender. You can test that with a multimeter to see what resistances you're getting with coolant cold, warm and hot.
- The gauge. You can test that with the resistors to see what movement you get.
- The wiring between them. You can test that with the multimeter, to make sure you're getting the same range of resistances at the gauge as you are at the sender.

With both sender and gauge testing, you've got to remove the wiring from the equation - test both right at their pins.

[Mudlark]

Multi connector on the back of the dash pod always worth an inspection when you get instrument issues. Sometimes get corrosion on the tracks, track lifting, dodgy plug etc

[MickeTJ]

I will definitely check the multiconnector.

I have now tested with a new sensor (Just kampers), and I got a little movement on the needle on the new gauge (about just over the bottom white line).
Then I tried with the old gauge and no movement at all.
I have made a new connection on the wire at the sensor.

How can I test the sensor? I have a multimeter. Do I measure Ohm? and in that case where do i put the connectors? one on the sensor button and ground on the side of it? I have seen someone test a sensor with a cigaret lighter on an old SAAB. but I have no idea what too look for or measure.

If its a faulty cable how can i test it with a multimeter? Or can I do so?

The engine, I think is getting up to temp. Its 25 degrees C here and I have it running on idle and the fan kicks in.

I have another sensor (Brickwerks) coming in today so I will check that as well.