Luego is now back from the professional fettlers (thought it best to get it runing properly before the clocks go back in the Autumn). Car runs superbly now but he did have one problem that flumoxed him for a bit (the job was strip, rejet and rebuild the carbs, fit Lumenition and rolling road it). After everything was up and running an intermitent problem started on the test drive where the engine would start to struggle then die. Eventually it was traced back to a faulty battery earth (killing power to the fuel pump) but having a further poke about he founf that the fuel pump shared a fuse with the indicators and is actually wired through the indicator relay. That's not correct surely. No relay own fuse the way to go? (if someone could explain what a relay actually does I'd be even more greatfull).

[Edited on 20/3/09 by norfolkluego]

Wired through the flasher unit (should have 3 terminals) or actually through a relay (4 or more)?? No its not correct anyway - no need to go anywhere near a relay with the fuel pump feed - simply a switched live (white wire generally) through a fuse and to the pump (unless its ECU controlled which it wont be).

Relay is a means of switching heavy load source such as headlights, fans, fuel pumps with a low current through a switch.
Example, you want to power a pair of driving lights, but you don't have a heavy duty dash switch, run heavy wire to the lights, then use a relay in the circuit to switch the lights on and off with a regular switch.

So (if I've understood), the dashboard switch actually switches the relay on/off, the relay switches the component on/off (lights in your example).
Right?

Related question, on a 7 type kit is the battery earth normally connected to the chassis or block (or both or shouldn't it matter). Mine was connected to the block, I would have thought it would have earthed the chassis via the propshaft/diff.

You should really earth the chassis and the engine - my old car had the engine earthed to the chassis and then chassis (off the same bolt) to battery

quote:

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Originally posted by norfolkluego
So (if I've understood), the dashboard switch actually switches the relay on/off, the relay switches the component on/off (lights in your example).
Right?

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RIGHT!

Had a good poke about with this today (incidentaly it's Premier Wirings loom, not a home made jobbie).
The rear loom specifies black/yellow as the fuel pump wire, checked and it is.
This should be the only black/yellow in the loom according to the spec. There is a black yellow going into the indicator relay but if I pull it out the indicators don't work. If I put the witre back in and pull the relay out altogether the fuel pump still works OK (indicators don't obviously). Does this mean the black yellow at the relay is not the same as the black/yellow at the fuel pump or haven't I proved anything?

Hi Norfolk
you might just have solved my problem with an r1 striker, It got its first drive of the year last week after a good service got 200 meters down the road and the engine just died!! messed about in the roadside for 10 mins , then hey presto fired back into life.
I drove to local shops all ok on the way back gave it a little welly around a roundabout and felt the steering heavy and thought I had a puncture, but no getting out and having a look the wishbone had snapped!! with both wheels pointing outwards .So not a good day!-Getting 2 new wishbones from mel at raw in 3 days here to spain -very good service I fitted these to go out on a classic car run today ,
finished yesterday morning. go to start it but could not hear the pump and did not fire up!! tried again a few mins later and heard the pump and it started got it hot switched it off .then 5 mins later got in for a blast and again it did not start and no pump, so I started checking the wiring and noticed hazards were working as were the lights but no indicators or pump also the coils as the carbs must be full but no firing,
As I did not build this car its a question of trying to trace where all the wires go and what relay does what ?I have 2 Earths 1 to block and 1 to chassis so I dont think its that, this car started out with a ford wiring loom but had a bec transplant so has had different wiring spliced in.so is there somthing I am missing or does any one have any good ideas

Paul

Paul,
According to my wiring diagram the relay should have three wires
1 Brown earth (I have 2 like you)
2 Black/Green O/S indicators
3 Black/White N/S indicators
I've got the above but Black/Yellow instead of Black/White and Black/Yellow is the fuel pump feed BUT this wire only runs back to the fusebox not the fuel pump (that is Black/Yellow) I think the wrong coloured wire has been used between the fusebox and relay (they are quite small and do look quite similar). Hope my problems were all down to the faulty earth which is now fixed, as I can pull the relay completely out without affecting the the fuel pump I don't see how they could be connected, could a faulty earth be your problem?
John

Normally the wire that comes from the fuse goes to one side of the indicator relay, the other goes up to your indicator stalk & then from there to the relevant indicators i.e. O/S or N/S when operated, the third is earth. If they have tee'd the fuel pump feed onto the positive side of the relay then realistically there is nothing wrong with that. All they have done is pick up a switched live so the fuel pump is only live when the ignition is switched on.

Alan...

cheers john and allan I will try and have a look at that later unfortunatley work stops play lol
Paul

Well Ihave just found the problem a faulty relay.
It seems to contol pump-indicators and brake lights and ignition unit
Now to put the car back together!!!

cheers

Paul.