Flashing temperature light on 1991 Golf Gti 8v. HELP PLEASE!

[G_T]

Hello,

I bought a '91 GTi with the coolant light flashing. Temperature is relative normal and only fluctuates a little.

I thought it was the coolant level sensor. So I shorted it with a paperclip and started the engine. The light still flashes.

So I bought a haynes manual. Relay 18 is to blame and it's hidden out of sight. So I take the dash apart and guess what. There is no relay 18.

I have checked all of these boxes;
http://forums.vwvortex.com/zerothread?id=3937100

None of them match my relays. The closest is the CE2 Box found here; http://www.xjamiex.com/mk2resource/electrical/CE2....

Any suggestions chaps? This is doing my head in...

[Dr G]

You've got 3 (I think) sensors on the N/S side of the head - all black if I remember correctly and all the same. Swap the connectors round and see if it makes a difference (they fail all the time).

[G_T]

I can see 2 sensors on the coolant pipe heading into the block, they're blue and black. The blue one is the ECU and the black the guage. The black is a little tempermental but shouldn't affect the running?

I'm now of the opinion that the relay 18 solution isn't relevant for me but being st with electrickery I can't say for certain.

The fan kicks in as it should, the coolant level is fine and a little murky but I suspect there might be a small leak (damned if I could find it though).

I'm now looking at changing both temperature sensors and the coolant level sensor, expansion tank, coolant pipes, thermostat and flushing the system to see if that helps. Holistic diagnostics are bloody expensive though so any advice is welcome!