No power to the fuel pump connection

Good afternoon,

Do you have a voltmeter and a test light to do some checks?

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

https://www.2carpros.com/articles/how-to-check-a-car-fuse

I attached the diagram of the fuel pump and need to do some checks to find out why you have no power to the pump.

Roy

the wiring diagram believe is wrong for my car's fuel pump - my is 2005 Jaguar S type fuel pump 4R83-9H307-AC which has six wire connection ..check voltage at each wire two wires (WG ) have around 1.6 volts each the other do not get any voltage at all .
Also checked voltage at inertia and its fuse both do get voltage at start .

also checked voltage at the fuel pump relay - it does seem to be getting voltage at least to wire terminals at start should i be getting voltage at all the other terminals ?
even swapped same relays around just to see if anything changes - same result.

Can I have the complete VIN number for the car?

Roy

SAJWA01T25FN30444.

forgot to ask ; inertia switch only getting power at one terminal is that normal ?
should it be getting power at both leads at start ? when I press on it doesn't seem to click understand that is when is tripped and needs to be reset ???
thank you for all your help. appreciated.

Yes, you should. If the button is depressed and you do not have power on both sides, the switch is bad.

Roy

Thank you Roy .
I need to verify that again today with a back probe test leads !
really appreciate all your help! Be well.

You are welcome.

Roy

Good morning Roy,
I tried bypassing the inertia switch, no change. no start ..

Can you go to the fuel pump relay? We need to do some testing at the relay.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Roy

yes I just did that so when you place your hand on relay R15 no movement felt or any clicks
power at terminals 30 - 12.4 volts 87A - 10.9 volts no power at 85,86,87 AT ALL .
i m using KZYEE vehicle super probe KM10 to test power and relay tester jumper Kit 56810

i don't get it !!! those are the secondary terminals should be getting power at 85,86 if I m understanding correctly..

according to link max fusible link or max fuse has shorted where would find those on this vehicle???

The control side gets its power from the ECM.

It provides power for 2 seconds with the key on for priming.

Then it will give full power once it is cranking and the ECM sees the signal from the crank sensor.

Roy

weird ! I m not getting any codes at all on the scanner i m using ICARSFOT i930.

should be getting codes if it is the ECM or crank sensor? oh yeah, pump not priming either and where exactly is the fuse for the relay?

many thanks Roy.

Crank sensor, yes but not on the ECM.

What color wire had voltage at the inertia switch?


Roy

white/green getting 12.4 when switch on. green 12.4 when start.. had a back probe wire at both of them.

The green/white comes from the ECM and should also feed the control side of the relay. If you have no power at the relay cranking, then you have a wiring issue between the inertia switch and the relay.

Roy

I have a 2005 astype electrical pdf according to that it is gu = green/ blue from ECM. where does the other wire black one goes to?

On electrical diagram fuel pump relay terminal 2 = 85 is black wire.
Terminal 1 = 86 is the green/blue wire. which has a diode in line there ?

And also before the relay there is a " diode " which i had already swapped from a spare at the engine compartment fuse box. i think maybe i should buy a new one unless there is a way to check resistance on those?

Black goes to ground. That is not the issue as you have to power to the control side.

No resistance check at all. It should have continuity going one way only. There should be no flow going the other way.

86. The power goes through the diode to the coil in the relay.

Roy

You're absolutely right Roy. gu runs from inertia to relay and other locations.

Gu wire also goes to 31 ii, 32,33, 34 all those locations 34ii is the fuel pump relay. what are the other ones ?

Should i introduce voltage via super probe to 86 on the relay to test it ?

You could try that. It will tell you if the system will work and confirm the wiring issue.

Roy

Roy, thank you so much for your help.. I need to go buy groceries let you know later if it worked.
You are the best man..

You are welcome.

Always glad to help.

Roy

unfortunately that method did not work not able to get the pump priming or going ..

Tomorrow i m going to run a wire from inertia lead w/u wire to terminal 86 on the fuel pump relay .... Maybe on the diode going to terminal 86.

I m still have not been able to figure out if there is a fuse for the fuel pump or is it powered by the ECM which has its own fuse.

Look on the diagram. There are fuses for the relay that must be checked as they provide power to the relay.

No, the ECM does not have a separate fuse for the fuel pump. If the relay is not getting power to the control side from the ECM, it is either wiring from the ECM to the relay or the ECM itself.

Roy

Great ! I kept looking at my electrical doesn't shown f23 for #3 (30) on the relay wiring. sorry should have been looking at your diagram .. Need to verify f47 for #5(87) which should be "hot all times " it is not ...
I will let you know. Roy if it is then - i probably have a short between fuse and relay wiring will that be correct ?
Thanks Roy.

Correct.

Roy

Hi Roy.


So i checked the fuses f23 it is always hot, f47 it is getting 12.5 volts. problem, i just don't see voltage at terminal 87.
So checked all 5 terminals on the fuel pump relay : terminals 85 none , 87a none , 87 none only 30 12.5 v 86 11.8 v (believe is ground side).
Tried a jump wire from fuse f47 t terminal 87, no luck...
What would you suggest next ? It almost feel the security system pats no letting it get started !! (had an experience with a BMW a while back) what warning light would it show ?

how can i disable the anti theft system?

You will not see voltage at 87 until the relay closes. When it does, 30 will send power to 87 and then to the pump.

I blew up the relay and attached it again.

No, you cannot disable it. That is factory programmed.

Roy

I apologize Roy, somehow i got confused!
Think i am understanding it right now. When switch is "on" position ii relay 1 (85) is energized via diode - then power flows to (87) ...then pump should be getting power .

i remembered checking power at diode base after removing it was getting power so maybe possible diode is bad or wiring to is shorted out ..

Thank you for your help ..

Correct.

You are welcome.

Always glad to help.

Roy

Roy one more observation.

my car's fuel pump wiring connector has 6 wires not 4 as shown on the diagram ?? I wonder why I m not seeing that?
I understand in that year there were two type of pumps.
I have the 2005 Jaguar s type fuel pump 4R83-9H307-AC model on my car...

I understand.

Please check the wires that I posted.

Roy

Hey Roy,

I appreciate your help.. still confusing on the color wiring to the fuel pump assembly I have six wire plug following order and voltage readings :
(1) red 12.3 V - (2) W/U 11.1 V -(3) B/N 0.0 V -(4) W/R 11.1 V -(5) B/N 0.0 V , (6) yellow 0.0 V

I just can't find the diagram indicating those colors!

Can you post some pictures of the relay and the fuel pump connector?

Roy

are you able to see the pictures?

any suggestions ROY ??

Yes, I got the pictures.

Trying to find a diagram for this.

Roy

I am sorry.. this car has been the most challenging.
i have had the same issue trying to find a diagram too. tried jumping power to the 85 terminal on the fuel pump relay no change also I swapped relays no change. a bit of history :
electric pump is new have not been able to get it to work. even tried putting the old one back no change..(old one was working just fuel pressure seemed to be all over), Fuel pressure regulator is new too.
just got some new diodes i am going to try putting those in DOUTH if that's going to solve it.. thank you again for all your help.

You are welcome.

Keep me updated.

Roy