helllp!!fuel pump rewiring!!

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turboloon

New Member
ok i've rewired my fuel pump as described in the how to section, but i ain't getting any voltage to the new wires everything was new i.e wire relay etc, now my question is should i take out the factory o.e fuel pump relay now that i have another one in line with the new wire as i'm thinking that maybe these 2 relays are working against one another..any help would be grateful!!:thumbsup:
 
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turboloon

New Member
12v switching relay with pins 85,86 ,87,30,also using 17 amp rated wire, witha in line fuse holder witha 20 amp fuse fitted, i wired it as i under stood it to be on the how to guide,i ran 2 wires from the relay, and the plug at the fuel tank end was cut (the live)i put the wire frompin 86 to the wire running to the front of the car and the wire from pin30 to the tail left on the fuel pump side.
 
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Animaldaz

Active Member
if you temporarily refit the oe set up and it works then there must be a problem with the either the new relay or wiring. Unless of course you have accidently blown the fuse without realising it.
 
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turboloon

New Member
just been out and checked the fuse it's all ok i'm getting power going into the relay but nothing coming out..ps cheers for feed back animaldz
 
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Animaldaz

Active Member
Can you feel the relay click? I would remove the new relay and check it off the car just to be sure its working, that will give you the chance to ensure your wiring is correct.
You have to check the wiring diagram on relays as they are not always the same.
 
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turboloon

New Member
yep done that and they weren't the the same i fear i may have buggered my new relay!!!is it possible the two relays can work against one another i.e because they're switches..maybe one is opening and closing the other....forgive me if this sounds stupid but i have no experince with stuff like this..
 
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Animaldaz

Active Member
If your getting power into the new relay then the oe one must be working. I thought there was quite a few members that have done this mod, its on my to do list but havent got round to it yet, so it would be nice of someone that has actually done it could comment.
 
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youngsyp

New Member
Right, I haven't read the 'how to' lately but, here's what I did:

Run a length of 30 amp cable from the battery, to the new relay, located next to the fuel pump cover. This should have a fuse no more than 12 inches from the battery.
Connect this to pin 87 of the relay. This is the new power feed for the pump, not the relay switching feed.
Cut the stock live feed at the fuel pump plug, and solder a length of 30 amp cable to the cable at the plug end. Solder the other end of this to pin 30.
Solder the other end of the cable you've just cut (the OE pump power feed) to relay pin 86 (this is the switch power feed for the relay).
Solder a short length of the 30 amp cable to pin 85 and earth this as close as possible. I think I cut the original earth feed from the pump plug and soldered it here too, then soldered a 30 amp earth cable to the fuel pump plug and earthed that to the same place as the relay.

You need to keep the original fuel pump relay in as, you're still using that feed, to switch the new relay on and off.
It should be noted that you won't get any voltage on the pump side of the relay, unless the fuel pump is priming (the 2 or 3 seconds after you turn the ignition on) or the engine is running. That may sound strange but, the fuel pump only needs to operate at these times so, that's how it works.

So, if you're trying to measure a voltage on the fuel pump side of the relay, without the ecu priming the pump or the engine running, you won't get a reading !

Paul
 
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turboloon

New Member
ok cheers for that youngsyp,it was a relay i bought from halfords so the wiring was slightly different, but there is a diagram on the back of the pack that it came in, any how done the above , and i'm aonly seeing 10.32 volts wich is still a improvement but not good, i'm persuming my earth is shit even though i have scotch locked on a earth and earthed to the car body, the o.e. earth wire feels 'soild' would i be ok to cut this wire and just earth the fuel pump side or could i earth both ends...?youngsyp where did you locate your relay..?
 
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turboloon

New Member
finally got my batt. voltage,, turns out i was taking voltage reading at the wrong time,i was doing it whilst cranking the engine over hence the drop in voltage , but when i did it when the pump intially primes it's self i was getting the batt. voltage.
 
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youngsyp

New Member
turboloon said:
ok cheers for that youngsyp,it was a relay i bought from halfords so the wiring was slightly different, but there is a diagram on the back of the pack that it came in, any how done the above , and i'm aonly seeing 10.32 volts wich is still a improvement but not good, i'm persuming my earth is shit even though i have scotch locked on a earth and earthed to the car body, the o.e. earth wire feels 'soild' would i be ok to cut this wire and just earth the fuel pump side or could i earth both ends...?youngsyp where did you locate your relay..?
Click to expand...
I won't bother with a reply then ! :lol:

Paul
 
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