[urq] Electrical question

Tony Lum tlum at flash.net
Fri Aug 5 19:26:34 EDT 2005


Thatcher Hubbard wrote:
> Hi all,
> 
>   Does anyone have any idea which pin on which connector to the back
> of the fusebox (under dash) provides the ignition-switched 12v to the
> stock ECU?  I've looked at the wiring diagram in my Bentley, which
> doesn't seem to contain that information, or maybe I just don't know
> how to read it correctly?

On the old fuse box, the switched +12V, aka the "15" line enters the fusebox at 
the black connector pin 2 or E2 as shown in the wiring diagram. It comes out(at 
least in theory) on pin A11 to feed the F/TCU and OXS frequency valve and fuel 
pump relay coil.
> 
>   I guess while I'm at it, does anyone have any idea how the fuel pump
> relay wires work into that?
> 
The fuel pump relay coil is fed by A11 and the F/TCU grounds the other end of 
the coil at pin 16.  The 30 contact of the relay comes from the H connector and 
the switched end (87) goes out to feed the fuel pump through a 16A fuse and a 
very long wire.  I wrote a long post regarding this wiring back on 9/18/2001 
detailing my fixes for this underdesigned circuit.

HTH,

Tony
'83 urquattro #302



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