[T3] (Fwd) 1969 Fastback Fuel pump

[Jim Adney]

On 7 Jun 2020 at 12:22, Tim Schiller wrote:

> There is a click when turning the key to on, but is something other
> than fuel pump relay. If I place hand on relay there is nothing when
> the key is turned on. 

It sounds like the fuel pump relay is not getting actuated. The single click 
you hear when you turn the key ON is the FI main power relay under the 
back seat. That energizes the FI brain and the brain should then turn the 
pump relay on.

Unless the engine is turning over, the brain will energize fuel pump relay for 
only about 1 second, so you need to take measurements quickly.

> Red wire to #30 is hot with 12V
> Blue & white wire to #86 hot with 12V with key on
> Grey or white wire is connected to #85
> Red wire to #87 registers 0 V when key turned on

I'm not sure of the colors of the wires to 85 and 86. When plugged onto the 
relay, one of them should be hot all the time and the other should be hot 
except when the relay is energized. The brain grounds one of those wires to 
energize the pump relay.If you don't see either of these going to zero during 
that first second, then your problem is related to the things that should be 
grrounding that wire. That means the wiring from the brain to the pump relay 
and the brain itself.

Start by getting a small jumper that you can connect between 30 and 87 on 
the relay. This should make the pump run. If it does, see if the motor will run. 
If the motor starts and runs, it means that the FI system is good, with the 
possible exception of the one transistor that grounds the pump relay wire, 
but it could also be the wiring between the brain and the relay.

Try this and get back to us.

> The above is with old relay and new relay

Sounds like the relay is NOT your problem.

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