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Red light flashing on and off in dash instruments.

Posted: Thu Dec 20, 2012 8:00 am
by G Beats
This been happening for a little while now this red light flashing on and off. It is were the temperature gauge is in the dash instruments.Some times I switch the engine off and it goes.And after a while it goes off as well.The plastic circle that is around the ignition barrel came off I thought might be to do with ignition barrel cuss of this ? The coolant level is fine and the alternator belt is fine as well as I have checked these both.Many thanks to all those who can help.

Re: Red light flashing on and off in dash instruments.

Posted: Thu Dec 20, 2012 2:55 pm
by mark1gls
The red flashing light shows low coolant, if the coolant in Ok then it could be the sensor or wiring to the sensor.
I have the same problem, I changed the sensor and I've still got the problem, sometimes it flashes other times it doesn't so I've just stopped looking at it now, been like it for 5 years!

Looks like this and it lives in the plastic expansion tank
http://www.gsfcarparts.com/parts/coolin ... vel-sensor

Re: Red light flashing on and off in dash instruments.

Posted: Thu Dec 20, 2012 8:42 pm
by G Beats
mark1gls wrote:The red flashing light shows low coolant, if the coolant in Ok then it could be the sensor or wiring to the sensor.
I have the same problem, I changed the sensor and I've still got the problem, sometimes it flashes other times it doesn't so I've just stopped looking at it now, been like it for 5 years!

Looks like this and it lives in the plastic expansion tank
http://www.gsfcarparts.com/parts/coolin ... vel-sensor
Ok great many thanks.I will check the connection as well on the of the sensor wiring.

Re: Red light flashing on and off in dash instruments.

Posted: Thu Dec 20, 2012 10:58 pm
by the edmundator
It's probably a fault with the printed circuit board that supplies the gauge. My 82 GTI has this problem as well, I'm trying to get hold of a new set of clocks so that I can replace it. If the temp gauge needle works correctly, it's unlikely to be a problem with the sender.

Re: Red light flashing on and off in dash instruments.

Posted: Sat Dec 22, 2012 10:54 pm
by mark1gls
the edmundator wrote: If the temp gauge needle works correctly, it's unlikely to be a problem with the sender.
On my DX engine Golf the temperature gauge works from a sensor on the front of the engine which goes to the top radiator hose, the coolant level sensor is in the expansion tank so they work of 2 different sensors.

Re: Red light flashing on and off in dash instruments.

Posted: Sun Dec 23, 2012 4:21 pm
by the edmundator
On earlier cars (like both of my GTIs) there is no coolant level sensor, so only one sender.

Re: Red light flashing on and off in dash instruments.

Posted: Sun Dec 23, 2012 9:25 pm
by mark1gls
I didn't know that so how does it know if the coolant is low?
I think the one in the expansion tank works from the two prongs making a circuit when the coolant is ok and when its low in the tank the circuit is broken so the light flashes, but I could be wrong.. :dunno:

Re: Red light flashing on and off in dash instruments.

Posted: Sun Dec 23, 2012 10:19 pm
by the edmundator
mark1gls wrote:how does it know if the coolant is low?
Only by the old-fashioned method of the driver stopping the car, opening the bonnet and having a look.

The flashing light is just to let you know that, in case you hadn't noticed the needle creeping up the dial, or the steam billowing out from under your bonnet, you really ought to think about stopping... now!

Re: Red light flashing on and off in dash instruments.

Posted: Tue Dec 25, 2012 5:07 am
by G Beats
Ok I will I tell at I have had a look at the plug on top of the coolant bottle I have unplugged it cleaned it and plugged it back in still the same problem. Next Ia'm going to clean it up with the connectors with electric connect cleaner and see if that will sort it if not will get a new plug and try that and after that looks like I will have to sort out another circuit board.And after that if it does not work ? :dunno:

Re: Red light flashing on and off in dash instruments.

Posted: Sun Dec 30, 2012 4:38 am
by G Beats
geebeats wrote:Ok I will I tell at I have had a look at the plug on top of the coolant bottle I have unplugged it cleaned it and plugged it back in still the same problem. Next Ia'm going to clean it up with the connectors with electric connect cleaner and see if that will sort it if not will get a new plug and try that and after that looks like I will have to sort out another circuit board.And after that if it does not work ? :dunno:
Ok I have tried cleaning it up the plug with electric contact cleaner it is still flashing next Ia'm going to buy a new plug.

Re: Red light flashing on and off in dash instruments.

Posted: Sat Jan 19, 2013 11:00 pm
by rustyinn
Did the new parts fix it ? I've got the same problem on my 1986 GTX. Starts flashing about 5/10secs after startup, coolant level is fine and is circulation. Temp gauage never gets over hot. Just damn annoying as your driving.

Dave

Re: Red light flashing on and off in dash instruments.

Posted: Fri Jan 25, 2013 5:40 pm
by ChrisPears
I used to have this, it would go off if I stopped and restarted the engine straight away. New sensor didn't fix it, never did find out what was wrong, it stopped doing it when I changed the engine, so it kind of points to a wiring issue. A loose connection or something that got fixed when I was wiring in the ECU etc.

Bit of a drastic fix for a flashy red light :hugegrin:

Thinking about it, I changed the expansion tank too, but I can't see how that would have fixed it.

Re: Red light flashing on and off in dash instruments.

Posted: Fri Jan 25, 2013 6:18 pm
by mark1gls
I think they are suppost to flash when you 1st turn the ignition on, then flash for a few seconds. So your might be normal, mine flashes when ever it feels like...

Re: Red light flashing on and off in dash instruments.

Posted: Mon Jan 28, 2013 8:50 am
by G Beats
No I have not brought a new plug for it yet.I have tried switching the engine on and off it stops it for a few seconds then it starts again and then carries on continuously until the engine is switched off.

Re: Red light flashing on and off in dash instruments.

Posted: Tue Feb 19, 2013 12:28 pm
by roccoGTX
I had this prob once in my Mk2 GTX with the temp light flashing.
I had oil going into the header tank, due to the oil cooler on top of the oil filter breaking down and mixing the oil and coolant. Also had overheating. There was no mayo under the rocker cover.
After a lot of invesigation we found the cause, but not before the oil contaminant had perished the coolant hoses.
Had to replace oil cooler, hoses, header tank and water pump and have the head skimmed as it was slightly warped.
Since then it's been fine.
I think that the oil coolers are becomin g a bit rare now.

Cheers

John