what causes the pink fuel relay in the mk3 mk4 escorts to overheat and melt.some say its the pump drawing too much power some say the relay itself,anyone know for sure mines has melted although cars only covered 57k. do i change the pump,relay or both ????

 

You create a new fuel pump loom with a (new generic) relay which then gives the pump full battery voltage. The pink relay is used simply as a trigger. The reason they melt is simply down to the fact even the newest wiring is 20+yrs old now and so current draw is usually huge and voltage is shit at the pump (which doesnt help your engine)

 

If you search the RST room or even the cossie rooms there are a multitude of posts with regards to this including the diagram of how to create the new loom

 

thanks guys currently restoring mine so loom is out,wanted to address this before refitting it

 

The problem is the draw of the pump, although the relay is rated for this, so should not be an issue.

The old wiring can add resistance to the circuit, thus cause the relay and wiring to heat up, not good! This also means the pump cannot draw the energy it needs UNDER load, which can cause a meltdown, as said!

Martin

 

ok so i need to change the wiring to the pump ,im assuming i need to strip the loom back and trace the wires from more or less fusebox/relay to the pump itself and fit a new relay.loom is out the car so will have to lay it out and have a good look at a glance it all looks good as the car is a low miler

 

low miles wont mean a thing when it comes to corrosion and breakdown of the copper wires.

 

No, if this is the issue, you need to rewire the pump from the battery, as it's this that is the problem.

A crude test is to measure the voltage, this should be what is at the battery ideally and it probably will be.

But when under load the extra demand can see this @ less than 12V, not good!

Martin

 

ok I am going to enter this debate both feet first! corrosion around the relay is the problem! This causes voltage drops which will generate heat! Very carefully clean up around the relay bringing the contacts to a shiny state! rust, gunk and corrosion are you enemies as is water ingress. I use a stranded escort cosworth fuel pump in my fiesta and it draws 5 Amps, nothing excessive. so the wiring should cope, unless it has been fiddled with and or corrosion has got in to it. -> immobilizers badly installed can stuff you right up as I have seen them installed on the power side of the relay!

Your relay is a coil of varnish coated wire that has had 20 years to cook its self and if water has got into the contacts on the power side it can get very hot too, so an OEM or better brand new one is a must! ( remember ford have been known to up-rate some of their relays and not shout very loudly about this so early models will not carry the load latter ones do) (see fan relay mk3 fiesta).

check the resistance and of the wires should be very small and voltage at the pump with it running!

PM me and I will get back to you if you have any problems.

 

come on in brendan the waters lovely,lol . doesnt look too corroded around the plug at the relay ,usual scorch marks etc will clean up the contacts and fit a new relay. not really any signs of water getting in under fusebox etc all pretty sound there is a pretty large hole (soon to be welded) around pedals floor pan etc