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Re: [T3] fuel pump relay failure?

On Thu, 2004-10-14 at 19:33, Jim Adney wrote:

> There is one red wire that comes from the fuse box; that's the hot supply wire.
> There is one red wire that joins up with a brown wire and heads forwards to the 
> fuel pump.
> In some years there is a 3rd red wire that is part of the wiring harness and 
> heads back to the engine compartment. It is only used on AT cars; on MT cars it 
> is cut off back there. You can see it if you look next to the wire that leads 
> to the oil pressure switch. I thought this usually was cut off in front, too, 
> but I may be wrong about that.
> In your case I would start by just connecting the supply and pump wire, and 
> then checking to see if the relay turns the pump on and off. If it doesn't, 
> then you may have your wires on the wrong pins.
> BTW, these relays very seldom go bad, and when they do you can usually bring 
> them back by just opening them up and cleaning up the contacts.

> You should start by checking to see if you get voltage between the two coil 
> wires (the ones in the plastic connector) for ~1 second when you turn the key 
> ON. If you do, but the relay doesn't respond, then there is a problem with the 
> relay. If there is no voltage there, then there is most likely a wiring problem 
> leading to the relay.

> Given what you've told us, I don't think this is a relay problem.

Don't forget the wire coming off terminal 85 of the relay and going to
the ECU. It connects to the FI harness at a single connector in the
engine compartment, by the forward bulkhead on the left of center. If
this wire is grounded, the pump will run all the time the key is on.
It goes to pin 19 of the ECU.

Russ Wolfe
'71 FB AT
'66 FB MT
'64 T34 (not running)
'65 T1 (not running)

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