Wierd electrics identify PCB card

[syncro4us]

Syncro 1986 2.1 DJ engine LHD
Pre owned 1986-1998 by the German embassey in London, then from 1998 privately and from 2006 by me
Now that Christmas is over and done with I have been tracking an intermittent fault on the internal heater/cooler blower. The current is getting all the way through past the switch so discovered a sharp tap on the side pannel frees up the motor and off it goes.
But..... in hunting around under the dash on the passenger side I came accross a pcb board with a few components on it. Couple of resistors, transistors, condensers and an 8 pin IC.
The board coverd in aging bungy foam has three leads terminating in a three pin connector.|On one side a brown, center / middle is white with black stripe and finally one black with blue stripe.
This coonects to a loom with identicle leads except the middle is a double white with black stripe lead.I cant trace back the wires unless I dismantle the front cowline around the heater
I have tried all systems and there is nothing that doesnt function properly.
I have been through both Haynes and Bentley manuals and the circuit diagrams show no circuit like this. Its Not a relay but I think its either a sensor or possible a timer.
Now I have to say that I have found some other redundant wiring that I have taken out, ie fine 0.5amp wires srunched up not doing anything so it may be part of an historical demobiliser circuit or some such as I have found a single white lead near the radiator with a wire terminating in a solid 15mm by 5mm cylindrical slug of metal.This goes back through the bulkhead .
Thought I would post this in case someone recognises the circuit and what it does as shure cant find a solution other than that above.
I dont like mysteries so have taken it out of circuit till I know what it does or did since the VW performs fine without it and we use padlocks on the doors etc to reduce its appeal as a take away.
Any one can help email kevinhjones@btinternet.com

thanks

Kevin

[silverbullet]

Sounds like you're describing the difflock warning light PCB, I think it should be tucked/dangling near the vacuum knob panel, hidden behind the front heater duct.

[hugomonkey]

sounds like what is being described in this thread
https://club8090.co.uk/forum/viewtopic.p ... hilit=diff" onclick="window.open(this.href);return false;