I have a DELPHI fuel pump but no wire diagram how do I find out what wires go to what wires

so what is there the 96 to 99 full size had a problem with the fuel pump connectors--corrosion causing short or overheating--- so when the pump failed you were advised to cut out and replace the connector with a new design one [flat]
Delphi FA10003 Fuel Pump Wiring Harness which are also color coded to the original one their was also a square to flat adapter so if you have the flat connector just splice to the correct color Bosch WHGM67XMOD Fuel Pump Wiring Harness

What year car? The factory changes colors or wiring frequently year to year.

You bought from Autozone,and now you have to splice,look at both and use the same wires from old pump to new one,look at both connectors and do it the same as in both plugs..

Did you check the fuel pump relay in the fuse center under the hood? Maybe you blew the relay and really didn't need to replace the pump. Did you recheck all the wired connections with a DVOM? Never ever replace anything as important as a fuel pump with out double checking all connection and checking for voltage before putting it all back together. Hopefully you didn't put the gas tank back in yet. Oh and you can swap the relay with one of the others sitting next to it i the fuse center, just remember to switch it back when you're done.

Then the fuel pump has failed most likely. It is electric of course and located inside the fuel tank, the fuel tank must be removed in most cases to replace the fuel pump, and don't forget to replace the fuel filter

I would recheck the wire hook up at the fuel tank. Usually when you replace the pump in the tank they should have given you a new fuel pump connector. You probably have a bad contact at this small harness.

Install only factory replacement to get fuel delivery constant per factory spec.

Check the wireing to the pump they had problems with it it tended to over heat and corroad there is a service bulliton on the prroblem #25215705and a kit with new wires and connector to resist over heating Icould give you the kit # but i got a DELPHI pump and the connector dosn;t fit a chevy pump

sorry napa fuel pump are know for that i a 17 year mechanic have seen the same thing at least 15 times this year,go to auto zone and get a duralast

Hello Tattedclacke,

I am not easy to get my feathers ruffled... but your "factory" drawing are worse than BAVARIAN... Took me quite a
while to determine your "GROUND" is the "br" (brown)
wire emerging from your PUMP... You have effectively
eliminated all other possibilities...

I don't understand why... but it APPEARS to return
to the driver area (no... not confusing it with fuel gauge)...
LOTS of opportunities for damage, corrosion or dirty
connections... !!

Since you were already DARING ENOUGH to jump
the BATTERY to the pump (I would NOT try)...
testing the GROUND might reveal your next quest.

Personally... (for wiring diagrams (factory is detached))
I would beg, borrow or BUY the BENTLY
book... or use a decent mechanics SHOP manual...
Amazon com Bentley Paper Repair Manual VW Jetta Golf GTI A4 Automotive

I think you are almost there... (I would NOT try)... but
Temporarily supply a local GROUND for your pump ...
(I simply don't do ELECTRICS at the FUEL tank - EVER).

ELSE
I am attaching the "Do it Right" recommendations
from Delphi... (please read)
More Information for DELPHI FE0723

As you are already into the tank... you can likely SEE
any issues with the fuel... However having BEEN THERE...
I would STILL take the additional step of evacuating and
cleaning the tank...

Read & heed the above "Do it Right" ... I will
only add that cleaning injectors with Berryman
Choke & Carb cleaner has helped wash away the years of poor quality fuel. Amazon com Berryman 0117 12 Chemtool Carburetor Choke and Throttle Body...

Hope this helps

Carnac the Magnificent