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Discussion Starter · #1 ·
Hi lads,
On my 88 Jetta, the temperature light is constantly flashing,
The needle never moves into the danger zone and the fan kicks in every time.
There is coolant in the flask, I've replaced the thermostat and the sensor switch
on the top of the flask and nothin has worked.
There isn't actually anything wrong, it's just annoying to look at.
Any suggestions?
 

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if the sensor is working, and the therostat is working it must be you clocks eh? try swapping in a different set off clocks, would rule that out anyway!
 

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Discussion Starter · #4 ·
Dunno..
The levels are fine, it's the red flashing light in the middle of the temp. gauge
 

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QUOTE (vwkev @ Mar 31 2006, 11:35 AM) <{POST_SNAPBACK}>Dunno..
The levels are fine, it's the red flashing light in the middle of the temp. gauge

I think it is the level, is the sensor at the top of the expansion tank connected right?? Possibly knackered??
 

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It is the level. The sensor could be covered in crap and not working. That has the old type exapnsion tank afaik, the one like on my jetta here:



If that is the type then you can unscew the sensor from the top of the tank, clean the 2 probes and put it back in and see what happens. It should work ok then.
 

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Yeh the sensor light should be level alright. If you disconnect it and put a piece of wire between the two terminals in the loom plug and see does the light go out, if it does then its the sensor in the bottle, if not then you may have a wire frayed back in the loom somewhere or your clocks may be a problem.

EDIT just saw Geos picture now. Does the old style bottle have a 1 or 2 wire loom going to the sensor???
 

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QUOTE (8valver @ Mar 31 2006, 11:55 AM) <{POST_SNAPBACK}>Still applies then.


Would do, the contacts can also corrode giving a bad connection and resulting in the light coming on, that happened to my caddy before.
 

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Discussion Starter · #11 ·
Cheers lads,
yea it's the same as geo's pic, 2 wire loom.

Allready tried that geo, unscrewed the sensor from the top of the bottle, it was spotless, replaced it anyway and it didn't work.

The loom must be knackered.

I read a letter in PVW recently, someone had the same prob in a golf and they suggested replacing the whole flask and pressure cap. Can't see how this would help
 

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Before you go at the loom, give the Clocks a swap,

15 years and a fickle little wire at the back of that led can be a recipe for DISASTER! (Sorry for the dramatics!)
 

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QUOTE (vwkev @ Mar 31 2006, 01:04 PM) <{POST_SNAPBACK}>I read a letter in PVW recently, someone had the same prob in a golf and they suggested replacing the whole flask and pressure cap. Can't see how this would help

With the later type round expansion tank you can't take out the sensor so have to change the whole thing.
 

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If you've ever ended up with oil or other gunk in your coolant that creates a sludgy deposit, this will collect in the reservoir over time and fould up the two contacts used by the level sensor, making it always open and causing the light to flash - it might be worth taking the tank off and giving it a good clean. Soak it in diesel or petrol and then give it a thorough rinse.
 
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