[T3] White wire?

[Jim Adney]

On 5 Nov 2015 at 0:37, Daniel K. Du Vall wrote:

> OK, Having a bit of trouble and it may be because I am using the wrong
> wire under the back seat of my 72 to turn off and on a relay that
> powers my ECU and ignition coils. 

That relay should only power the brain, not the coil.

> The wire is a white one can't seem to find it in the Bentley to
> determine where or what its used for. Using this wire does engage the
> relay and am able to start and run and run is the problem. After
> turning the key off things stay in run mode till I pull the white wire
> off that I am using. IS there another wire I should be using that runs
> back there from the key to do this task? Is the spare red one that
> runs to the engine compartment an option?

Sounds like you've got the wires on the FI main power relay mixed up.

That relay is shown on the FI wiring diagram, not the main one. There 
is 1 wire that comes from the ign. sw. I'm not sure, but I don't 
think it's white (perhaps red.) That wire connects to one side of the 
relay coil. The other side of the relay coil goes to ground via a 
brown wire that ends under the relay mounting screw.  

There should be 2 white wires that run toward the rear of the car. 
Those both carry power to the brain. They connect to the normally 
open relay contact, where there are 2 terminals.that are the same 
inside the relay. There's a red wire that runs from the battery + 
terminal to the common terminal on the relay.

You can either figure out which relay terminals are which by using 
the terminal numbers from the FI wiring diagram or by using an 
Ohmmeter. The 2 coil terminals will have 15-200 Ohms between them. 
The 2 output (normally open) terminals will have ~0 Ohms between 
them.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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