arggh!! temp guage low level light!!!!

Post by **banana** » 15 Nov 2005, 09:34

Its driving me nuts. I' ve replaced the sensor, ive cleaned the probes with emery, Ive spliced the original cable into the sensor and added new spades, ive wd40'd it, ive covered it it insulating tape but still it comes on on first start up. I can get it to go off after warm up by turning off ignition and on again.... why does that work? but why is it doing it? has anyone found the holygrail of faulty water sensors. My water level if anything is higher than max.

Post by **Grun** » 15 Nov 2005, 12:40

Banana,
I have not had any problems in this area, and I am not an electrician, but looking at the dreaded Haynes wiring diagrams, assuming it is not a bad connection somewhere, the manual shows an electronic control unit, (also called 'Switch unit for coolant shortage indicator' in another illustration). in the circuit.
It is shown as fitted in position 3 on the relay plate above the fusebox.
That is third from left on the top row (of two rows). There are many variations of the relay layouts apparently. May be worth a look.
Mike

Post by **banana** » 15 Nov 2005, 13:24

Thanks Grun .....is this the fuse box in the glove box or the black box in the engine. And when I find it what will i be looking for? Is the haynes manual worth buying if I have a deisel do you think?

Post by TD » 15 Nov 2005, 13:31

do you mean it keeps flashing all the time?, as it is designed to flash on ignition ,as a self check, for some seconds.
Other than that it is a 'disaster light' and you have seconds to stop if it is for real.
Usually, at this age the earth contacts are getting poor, WD40 is not the stuff to use, vaseline(petroleum jelly) is the stuff for contacts.
The expansion tank should always be full if the system is correct.

Post by **NOT ANOTHER LEAK** » 15 Nov 2005, 14:00

ive posted this reply before.on my van if i turn the ignition on and turn the engine over straight away the light never stops flashing full stop!.but if i turn the ignition on and wait 30 seconds before turning the engine over the warning light stops flashing straight away,this happens every time.i found this out after going thru all the things listed by yourself and none of them worked.its a long shot but it may be the same for your van

Post by **Grun** » 15 Nov 2005, 14:17

Banana,
Its the fuse box in the glove box. I have the petrol version of the Haynes manual and find it useful. The manual known as Bentley is the best I believe, although I have never seen one, nor do I have any diesel experience. As TD says the light flashes when ignition key is turned on, but normally goes out after a few seconds. This is on petrol models, the diesel drivers will no doubt confirm this. The Haynes wiring seems to show that the 'Switch unit for coolant low level indicator' J120 in the diagram, is also hooked into the temp sender and gauge circuit, but with no internal wiring of J120 shown, it is not possible to see how it operates the two functions, temp and level.
Keep trying.
Mike

Post by **banana** » 18 Nov 2005, 11:09

Thanks for all the tips. I found the relay. On my deisel there is nothing else until the third space from the left. I removed it looked at it and put it back. No joy! So tonight ill try the 30 second pause with ignition on. The trouble with the light flashing is it brings makes bad memories of my head gasket and I start to sweat.

Post by **banana** » 21 Nov 2005, 11:04

tried the 30 sec delay. Didnt work!

aarrgg

Post by **NOT ANOTHER LEAK** » 21 Nov 2005, 11:51

only one thing for that then,put a bit of tape over said flashing light and bingo no more flashing(that you can see that is)
hope you get it fixed tho sounds a pain in the a***

Post by **Poseidon** » 21 Nov 2005, 15:33

My 1.9 DG does the same, the light flashes for the self test, but just keep on flashing.
I find that if I switch the ignition off for just 1 second, then back on again the flashing stops..... most odd.
I've had my van 2 years and have never checked the water levels, thats a little job for tonight I think....

Website · Post by **dbroada** » 21 Nov 2005, 16:30

just a warning tale from me.....

on holiday this year (French Alps) the light started flashing. I carefully drove to the first parking spot I could find and checked the water level. It was full. Restated and no flashing light. Next day, same thing. This time I look at the circuit diagram in the manual and find it's a "break" switch - flash on error. I check the wiring and found that one of the wires had broken in its connector and only making intermittant contact.

With my mind at peace I then drove across France and into Spain with the light flashing and me safe in the knowledge that the faulty wiring would be fixed at the next campsite. Just as we got into the first traffic jam in Spain I saw the temerature rise, and continue to rise until I finally stopped with steam pouring from under the van. Fortunately I saw the temperature gauge go high and stopped before serious damage was done.

It's fine to ignore the flashing light but do keep an eye on the other gagues at the same time!

Post by **NOT ANOTHER LEAK** » 21 Nov 2005, 17:22

dear mr moderator,i think we need a forum just for flashing water warning lights

Post by **angry vanagon** » 21 Nov 2005, 22:50

i had the same problem on my van turned out to be the relay try swaping this for another one. by the way the relay is the same part as the golf mk2 (84-91) so this should make it easier to find one at the scrapyard

Post by **tonytech** » 21 Nov 2005, 22:59

The red warning light on my Polo (same dash layout ) is just as irritating.
Every now and then for no apparent reason it will start flashing.
A good bang on the dash usualy cures the problem so I suspect a loose connection to the PCB.

T

Post by **Poseidon** » 22 Nov 2005, 14:45

I got outside in the dark lastnight and had a check in the water expansion tank and overflow. The overflow was empty and the pressurised tank was only half full. For now I have topped it up with some of the pink halfords pre-mixed antifreeze.
When I get a chance I'll drain and flush the whole system and start again!

I did notice that it looked like both bottles looked "muddy" I'm praying that my engine hasn't rusted away!

Anyhow, the anoying blinking light no longer blinks now. . . so I'm happy till I find out what real damage there is....

Club 80-90 Forums