Temperature Gauge Shoots Up

[toddydal 1]

as tiltle says when i put ignition lights on my temperatuer gauge shoots up to the top and stays there,i have unplgged the temperature gauge wire and makes no differance,i traced the wire back to a brown plug and unplugged that aswell and it still stays up,when i earth the wire out the temp gauge goes right off the scale,,,,any ideas,,,,,its on a 1.6 205 gti

Edited February 21, 2010 by toddydal

[grandos 16]

Check the wire to ground, as it could be shorted some where.

[toddydal 1]

at the moment it goes up to the red light on the gauge but when i earth the wire out it goes past the red light,well it goes right off the gauge

[DrSarty 90 1 Cars]

It's because you type too many commas.

 

 

 

 

 

 

 

(Joke)

 

Seriously, it has to be a ground issue. Look up the brown multi-plug guide. Dreamweaver's one is the most comprehensive as it shows the 6 & 9 pin brown plugs under the dash going to the (crappy) plug on the gearbox.

 

One of the wires in the 9 pin plug under the steering column (pin#4 IIRC - going from the end which has the 2 reddy brown wires which are the reverse switch) is for the guage. Pin#3 is for the warning light.

 

I'd pull the 9-pin plug open and test pin#4 to earth. The needle should shoot up. Earth pin#3 and the warning light should come on. This way you're testing whereabouts the fault lies and ruling out your clocks.

 

Then you could do the same from the (crappy) brown plug, which corrodes to buggery as it comes in contact with a lot of water being by the gearbox. I can't remember the pin number on that one, but pulling that open and doing the same test will isolate the part of the circuit that is grounding out.

 

There may be an even simpler fix, which is that either you have the two connections on the water/stat housing the wrong way round, or the sender itself has gone tits up. Most likely the latter. As for which one is which (sender to guage or switch to light), the sender is the smaller of the two, but you'll have to remove it/them to see that.

[toddydal 1]

cheers drsarty

[TaffyTim 6]

It's because you type too many commas.

 

 

 

 

 

 

 

(Joke)

 

Seriously, it has to be a ground issue. Look up the brown multi-plug guide. Dreamweaver's one is the most comprehensive as it shows the 6 & 9 pin brown plugs under the dash going to the (crappy) plug on the gearbox.

 

One of the wires in the 9 pin plug under the steering column (pin#4 IIRC - going from the end which has the 2 reddy brown wires which are the reverse switch) is for the guage. Pin#3 is for the warning light.

 

I'd pull the 9-pin plug open and test pin#4 to earth. The needle should shoot up. Earth pin#3 and the warning light should come on. This way you're testing whereabouts the fault lies and ruling out your clocks.

 

Then you could do the same from the (crappy) brown plug, which corrodes to buggery as it comes in contact with a lot of water being by the gearbox. I can't remember the pin number on that one, but pulling that open and doing the same test will isolate the part of the circuit that is grounding out.

 

There may be an even simpler fix, which is that either you have the two connections on the water/stat housing the wrong way round, or the sender itself has gone tits up. Most likely the latter. As for which one is which (sender to guage or switch to light), the sender is the smaller of the two, but you'll have to remove it/them to see that.

 

Thanks for typing this all them years ago, I'll be doing this test and was looking for which pin in the cabin controls the temp gauge , pin 4 it is then and pin 3 for the warning light.

 

From another post it looks like pin 7 on the brown (crapy) multiplug in the engine bay will be the one i need to test for the coolant temp (wire 47a) and pin 6 is the warning light (wire 47).