My fuel pump relay switch

[rabbitnothopper]

using a large relay I had from the 91 cabriolet I scavenged
relay 57 was the tallest with the best pins

remove "GUTS" keep the pins on the bottom
wire in the fuse to the switch
important:
keep the fuse connected to the switch pin which is NOT connected when "off"
when switched ON you want the fuse inline to the battery to make contact

wired like this:
pin 30 battery -> fuse -> switch OFF / switch ON -> pin 87

sorry no inside pics... but my switch fits inside the relay housing perfectly
and of course it is very tight to squish it all down inside

purpose of the fuse outside the relay of course is for replacement
10amps is sufficient
if you can find a fuse holder which would mount beside the switch itself that would work great
or a larger switch with a fuse holder in itself!

Purpose of switch:
used to diagnose fuel pump, fuel pressure, and injectors

fuel pump works? yes
fuel system pressure 68-78psi? yes
fuel injector spray pattern good & even flow rate? yes

[Chia's_MkII]

...awesome piece of engineering there!

Regards,
Chia

[wikiwiki83gti]

though of doing this when my friends went through 3 in a week and we kept having to jump the terminals
nice work

[rabbitnothopper]

hey this tool works great to check if your pump works
also works to get the car running

what it doesnt tell you is that the ground wire for the 85/86 signal isnt grounded
which is why the relay itself didnt work.....

need to fix my ground wire and FP relocate socket

[volks trippin']

awesome idea, need to make me one!