Fuel pump relay

http://www.autoelectricsupplies.co.uk/product/174/category/36

 

Thanks for your advice, i bought the relay in the link above and fitted it today. I wired it up, turned the engine over lots of times but there was still no fuel pumping, i tried agian and noticed that the live feed for the fuel pump was starting to melt! i had taken the live feed from one of the carburettor solenoid wires(this is the wire that melted) also the fuel pump earth wire was warm, and also noticed a black wire from the steering column(ignition switch?) was getting hot. Any idea what i have done wrong? or is it the wrong relay?

 

This is the relay

 

What've you connected to which terninals on the relay?

 

Wire to the pump shouldn't be able to melt as it will blow the inline fuse that you have on it first - wont it.

 

But what have you connected to what? Sounds like you're shorting the ignition feed.

 

• oil pressure switch wire -> relay 85 | relay 86 -> oil pressure wire harness
• 12v -> pump -> relay 30 | relay 87a -> ground

 

Ok,

Going back over this you want 85/86 connect through the oil pressure switch

then you want a switched ignition feed connected to 87a
and terminal 30 goes to the positive on the fuel pump.

 

Beat me to it

 

the pump side should look something like this:

12v ignition fed supply to relay 30 then 87a to pump then pump to ground

 

Thank you, looks like the ratwell wiring instructions are wrong then

 

Is it ok to supply the fuel pump from where i had it (carb solenoid) i will also fit an inline fuse.

 

Should be fine...

 

If the way you put it up earlier was from Ratwell it not wrong, but does rely on your fuel pump not being earthed to chasis/body in any way its basically switching off the negative side to break the circuit. switching the positive is just much simpler.

Provided the wire size is big enough, is it also running your choke/s ?

Personally I've got mine running on an actual fuel pump relay which is triggered by the coil firing. and fed direct from the battery.

 

Heres a picture, the blue wire to the left is going to the fuel pump +

 

So are you saying that i could leave the wiring as it is(the ratwell way) and just remove the fuel pump earth from the body?

 

VERY melted! and how is the feed to the coil?

 

You could, but i think it would be much simpler to switch the positive. and make sure its all fused!

 

The wire to the coil is fine, it was only this wire that melted

 

I don't mean to sound cheeky, as i appreciate your help very much, but what could be more simple than just removing the fuel pump earth? which ever way i do it i will fuse the live feed. I would prefer to just remove the earth, if its safe to do so? as i have the wires to the relay soldered and sealed with heat shrink sleeving, not a big deal to break them but would be better if i don't have to.