Thread: Disco 1 won't start

This is curly but (your quote): checked all the fuses have power going to the relay but not coming out.

By your description the problem lies in the relay...


whats after the relay to stop transmission?

GQ

Originally Posted by bigmac

Hi all need help, 94 300TDi disco will not start. It is an Elec problem can not get power to the Injector pump through the relay.
can start it by bypassing the relay and going straight to the injector pump but have to pull the wire off to stop it.
Have put in a new relay, checked all the fuses have power going to the relay but not coming out.

HELP PLEASE
thanks
Neville

Have you checked the supply to the coil on the relay - as you know a relay is an electrical switch that uses a smaller signal wire to sitch a larger supply.

Normally four terminals are use, incoming from the signal to the coil, outgoing to earth - if a 'normal relay is used the terminal numbers would be

85 signal in
86 Earth

These could be the opposite way round,

Then you have the power (which is switched - by the signal)

Again on a normal relay the incoming power comes in on

Terminal 30 -

And goes to the pump on

Terminal 87.

I am not sure on a 300 tdi how things are hard wired - but generally you turn on the ignition - power is applied to terminal 85, this switches the terminals 30 and 87 - applying power to the pump.

Check the fuses, with the ignition on you should have 12v on terminal 85, 30 and 87

When the ignition is switched on - does the relay click

The relay is a 70amp with six pins it can only be connected up the one way. there is 12v every where except on the wire going to the pump.
No cannot here it click.
Will take both relays to an auto elec tomorow and get them checked because the new one is a $140.
Thanks for the quick reply

This sounds suspiciously like an alarm spider fault...Does your disco have factory imobiliser, IE a key fob with 2 buttons?

JC

Originally Posted by bigmac

The relay is a 70amp with six pins it can only be connected up the one way. there is 12v every where except on the wire going to the pump.
No cannot here it click.
Will take both relays to an auto elec tomorow and get them checked because the new one is a $140.
Thanks for the quick reply

That 7 pin sucker is the glow timer relay.

They are silent in operation as they are a solid state timer unit

I say alarm spider fault.

will there be money on this?

JC

No it dosen't have an imobiliser or any of that fancy stuff it is put the key in the door and turn.

Oh well, back to the beginning... HAve you checked the fuse with the 'lightning bolt' and engine illustration on it? 10 amp I think.(red) This is the one for the supply to the injector pump wire. Sorry I can't remember the fuse number or position, but it has that pic on it. It isn't in one of the satellite fuse arrays, it isn't far from the ABS one from memory, under the dash / steering column.
This is the same fuse that supplies coil + in the V8.

JC

The only info I have for a 300 tdi has a injector pump driven by the gears off the crankshaft. Must be an earlier model.