# Low voltage fuel pump connector



## sinful (Jan 4, 2012)

Hi all. 

I ran into a problem and can't figure it out why. Basically when cranking the motor over the external fuel pump is not working correctly. It does start for a second or so and then it stops. dead pump right? but...

I removed the pump and plugged directly to the battery and to my surprise it works perfect !

So I went ahead and did some further testing. Using a multimeter tested positive and negative plugs at the fuel pump connector with engine cranking and was only getting between 9-10 volts steady.

Am I missing something here? would the fuel pump should still operate at this low voltage? maybe the started and cranking the motor are taking up the missing volts? I'm lost because when turning the key on with engine off there is no power at the fuel pump connector (until you start to crank the engine you get the power).

any ideas?


----------



## sinful (Jan 4, 2012)

testing the battery directly I'm getting 12.6 volts. motor cranks fine. this is an old nissan truck 85-86


----------



## sinful (Jan 4, 2012)

I'm just trying to help out my next door neighbor. he's an old guy like in his 70s and seems he has no funds to fix it. I'm just trying to help him


----------



## sinful (Jan 4, 2012)

found the solution

apparently the relay gets fed 10 v to 12 v got this by testing the relay connector with a multimeter. I removed the relay and directly pluged the fuel pump with a long wire to the relay connector and guess what? the fuel pump still didn't come on and I could here a buzz sound coming from another box near the relay connector. that box is called in-tank pump controller made by Jideco and the part number is 28545-89900. It has four tiny screws at the bottom and a bracket where the relay also attaches to.

So the Intank pump controller box was toasted. Unfortunetly I couldn't find a replacement box here in Mexico so a local electric genius repaired it for me. It came out perfect and only charged me like 2dls.

Apparently is a very common issue for these Nissan trucks. FYI 


by the way is located on the passanger side above the kick panel speaker way inside the dash. I had to remove all the dash bolts and slightly pull the dash out without disconnecting anything. just enough to make room for me to get a small drill with a philip tip to get the two screws out that hold the box. it was near impossible to loosen them with a regular philip screw driver. not enough room.


hope that helps anyone who runs into the same issue.

thanks


----------



## José Antonio (Nov 2, 2019)

sinful said:


> found the solution
> 
> apparently the relay gets fed 10 v to 12 v got this by testing the relay connector with a multimeter. I removed the relay and directly pluged the fuel pump with a long wire to the relay connector and guess what? the fuel pump still didn't come on and I could here a buzz sound coming from another box near the relay connector. that box is called in-tank pump controller made by Jideco and the part number is 28545-89900. It has four tiny screws at the bottom and a bracket where the relay also attaches to.
> 
> ...


----------



## José Antonio (Nov 2, 2019)

Do you have they phone number of the person in México who repair your relay?
Tks


----------



## Mirotau (Nov 29, 2019)

Friends I have sane issue with my Ichivan 1991 relay off , so please the anem contact of guy to repair it in Mexico..Thanks.


----------



## smj999smj (Jan 1, 2006)

You probably won't get a reply from "sinful." He hasn't had any activity on this site since 2013.


----------

