RED FLASHING HEATER TEMPERATURE LIGHT

[firetrader]

I have developed an issue on my dash (1985 T25 -1.9 Petrol).Its a red flashing water temp light - checked water levels in radiators - checked blue cap on radiator, its not an overheating issue? It goes out when I turn the lights on? So it looks to be a dashboard issue? Had it off , looked at connections which are shoddy, cleaned with electrical cleaner and put back but its not remedied it? Has anyone got any ideas - many thanks .

[Jim San]

Did you check all the earth crowns, as they seem to be cause of many a problem.

I had the same issue on mine, mine was a slack connection on to of the bottle, slightest touch and it got upset

[Robsey]

Definitely sounds like a dirty / loose / corroded earth issue to me.
As said, check your earth crowns at the bottom of the left A pillar.

[Smiffo]

When looking behind the 'clocks' did you check the blue ribbon? ( which is like a flexible printed circuit board spanning across the entire width, and ends up on the plug I suspect you cleaned already. )

If you have a leak, water ingress will get in there and corrosion causes all sorts of weird happenings.

[AngeloEvs]

After checking coolant levels, condition of wires to the coolant level sender etc, remove the coolant level warning module. It looks like a relay, is numbered 42 or 43 and located close to the fuse box on pre 1986 vans and in the fuse box on later vans. If the coolant level warning led continues to flash then the problem may well be at the dash, the temp gauge, loose temperature gauge securing nuts or intermittent connection at the 10v regulator socket ( located on the pcb foil).

If the fault clears then all the wiring to the coolant level sensor needs to be checked, particularly one of the wires which connects to the bodywork from the level sensor.

module (42 or 43) is earthed at the crown earths close to the fuse box and this is often found to be in a poor state - a poor module earth will trigger the led so must be checked.

[firetrader]

Thanks everyone for the good advice, had done my best to check what has been mentioned - there were a few uncertainties though as I am am not so good at the electrical aspects. Couldn't quite see the relay marked 42 0r 43 ( my van is a 1985 wonder if its different?).

The darn thing decided to play up when it wants, thought I had mastered it, cleaned you as much as I can behind the dashboard but it is in relatively poor state behind there but other than this flashing light it all works?

The light is on at the moment - yet goes out if I turn the lights on which makes me think its electrical -probably  the earthing you mention but I cant locate the area referred to for the relay - getting a bit scared of messing too much as I need it at the weekend, perhaps will see how it goes -if still flashing after the weekend may tinker some more - need to locate the earthing area I  feel. (PS cleaned up all of the connections behind the dash). Had past behind the dash issues- no water egress at all fortunately.

[AngeloEvs]

Early vans, the Module 42 (43) is located on the 'A' pillar close to the fuse box and the Earth Crown.   There are a number of earths at the crown including the Headlights, Radiator, module 42, etc,  which is why it is imporant to check the condition of the spade connectors at the earth crown itself.

[ZsZ]

Some useful info on the topic:
https://www.thesamba.com/vw/forum/viewt ... 7&start=60

[firetrader]

Many thanks for the comprehensive info received. I decided to start again and retrace my steps. I started in the engine compartment checking fluids and blue cap etc again. I doing so I cleaned up the electrical spade connections again fixed to the water coolants tubes, when I tried to start again the red flashing light went out, I hope it doesn't return now, tried it three times and each time its gone out ...phew hope its sorted... many thanks. 

[Robsey]

Excellent news -

Sounds like you've got it sorted.

I always quote that 95% of faults are due to dirty, corroded, damaged or loose connectors or tired old wiring.
Always good to look at the 'free' fixes before looking at replacing any parts.

Good to ensure that any cleaned connectors are given a dab of petroleum jelly (vaseline) to keep out moisture and are fitted securely -
give the female spades a gentle squeeze to ensure a tight grip on the sensor spade.

[firetrader]

Thanks all for your help.