Red light flashing after dash lights stop working

Another day another problem but hey ho we still love them. Anyway I've developed a small problem I hope. Basically one day last week the dash lights went out (so I gave the dash a gentle tap above the cluster) and then the temp warning light started to flash its head of aswell as the gauge keeps going all the way up after a short period of running and the fan only kicks in some times. First of all I thought the thermostat and all that so I've replaced every single thing I could think of so thermostat, fan switch, fan, water pump, but the problem hasn't gone away but the red light has got worse it's almost constant unless I'm giving it some beans then it will turn off. I can't for the life of me work out what's wrong I've read about the sensor in the expansion tank but I don't have one of them in zoey. Oh she's a 1986 cabby with a 1.6 auto. Any help would be appreciated. One other thing I can see a brown wire behind the dash that's a spade connector that doesn't seem to have a home.

I would think that you need to verify that your 10v stabilizer is working, or you have a mylar circuit issue.

I would validate that you have 12V battery on pin 14 black of the cluster.  Verify that you have ground on pin 2 brown.
and that pin 2 is 12v to pin 14.

The middle leg of the voltage stabilizer is ground, make sure that that and the pin 2 are the same.

The other two legs are 12V battery from pin 14.
And the remaining leg is @9.5 to 10v.

If that is working then your issue is a cold solder joint on the water temp gauge.  I have how to's that may help you in the Archive Section How-Tos.  

View topic: My DIY list of things for a 90ish Cabriolet (digifant2) part 1 - The Mk1 Golf Owners Club

under the electric.
1990-1993 repairing your flakey water temp gauge.

86 is the same.

Everything seems to be working fine all the correct current and the temp gauge seems fine it deflected as it should. So I'm still stuck

It the red light ment to still flash while testing it

Then If as you say you have an issue with the
gauge, as it has power in from the 10V stabilizer
Ground from the ground, and the input from the sender.

So if the sender has been replaced, and it happens well, then I suspect that you have issues inside the gauge itself, as that is where the circuitry is for setting the light off.



The top leg off the gauge is the flashy flashy light.



With these Critters, I suspect the grounds first, and the
Gauge second…. but in 4 of 4 cabbies I have owned, (89, 90, 92 and 93) I have had to resolder the connections on all of them inside for cold solder joints….

If your gauge studs are corroded, then you will ned to polish them up….  

The thing with 80's electrics, is it voltage sensitive….a little as .25V can set circuits off.

If you have changed everything and added a piece of tape behind the mylar to Plump It up to the connector.

If you have added a frame ground to pin 2 as in splice it in.  You are left with it being internal to the gauge.

I might have got hold of another cluster to double check everything is fine before I start taking the temp gauge apart.

One of the previous 15 owners has tried to fit a mk2 Rippon to the back of a mk1 clock muppets. That's why everything seems fine until I plug it in.

I'm not great with electric but I have read there should be a relay above the fuse box, No 43 or possibly No 42, pull that out and see if the light stops working. Clean up connections and make sure all the plugs at the back are in.

I did all that and everything did what it was ment to. Then I borrowed a mates cluster and found out mine is completely wrong with the blue Rippon on the back someone has put some how managed to put the blue Rippon on a set of golf a reg clocks. So I'm in need of the correct clocks for the car.