burned up fuel level guage grounds? please help

[1Gina2G]

Okay everyone, I've posted about this before with no end results as this is a worse case scenario for the fuel level gauge, but I'm guessing I've found the culprit to the problem..IF I found the right set of wires. Even if, I'm stumped on what to do next.

You must be logged in to view this image or video.

^^This picture shows a view of the drivers side floor area, with the seat & carpet removed. Theres a pair of 2 plugs for the electric seat motor, and 2 ground wires that bond to the chasis...these grounds were mentioned in other threads to operate the fuel level gauge...hopefully this part is true, but I'm not %100.
First I tried restripping & rekrimping new ends to the wires, right away the wires felt brittle and are easy to snap, the newly stripped copper is not shiny at all but appear to be burned up. I proceded to follow the wires back to the main harness running along the door edge, cut after the splice to bypass it, restripped the wires there and still burned up. The wires are blackend all the way throughout the wire, has to be burnt up instead of corosion..

Peices of the burned up wire were tested with a working OHMs meter and it's possible to probe for continuity but sometimes would not ohm/zero out.

What I dont get is the wire harness itself splits off to the back of the car for the rear lights most likely, and a keyless entry module..I don't see the ground wire pairs running to the keyless though, where do they run exactly, how would I replace them? are these the correct wires?


To recap on what's already been checked
the fuel level gauge itself definatley works for 2 reasons, the yellow wire at the sending units will fill the gauge up when manualy grounded out. The gauge cluster was tested out with an ohms meter, fuel level gauge readings checked out %100.
-both fuel sending units have been replaced for different reasons and also check out with the ohms meter with the floater, as well as manualy MOVING the floater with the fuel unit pluged in with the keys on in the ignition with no response from the fuel level gauge.

You must be logged in to view this image or video.

 

[Selling4G63TParts]

I was going to tell you to check the float but you have done that. I had to replace my fuel pump in my GSX and could not get my gauge working. It ended up being a bad wire so all I can tell you to do is keep trouble shooting the wires.

 

[1Gina2G]

The problem really has to be in the wiring, does anybody know the path of the fuel gauge wires, anywhere they can be easily located other then at the sending units? they obviously run underneath the frame on top of the gask tank somewhere but where else do they come up at?

I feel like I'm tracing the wrong wire, yet the wires under the seat are burned up, with the drivers seat connectors fully functional.

 

[luv2rallye]

Why don't you just ground the black wire right at the passenger side sender unit and be done with it? It's the same wire as the one under the driver's side floor area, just at the sender end so you're grounding it there instead.

FYI: Sender wiring explanation:
2g AWD wiring:
On the stock setup for AWD there are 2 senders in the tank that are connected in series - one on drivers side, one on passenger side. The fuel gauge goes to the drivers side first in a yellow wire. This is the one if grounded should make the gauge read full (when key on - takes a minute). The drivers side then goes to the passenger side in a yellow/black wire. If grounded, the gauge will read something (between halfway and full) depending on the drivers side sender position. The passenger side then has a black wire to ground. If either this black wire is not grounded or the yellow/black between the 2 senders in not connected, the gauge will not work.

In addition to all this there are also 2 wires to run the fuel level low light. They are (on AWD) a yellow/blue from gauge to drivers side sender, and a yellow/black (different than above one so don't get confused) between the driver's and passenger's senders.

 

[1Gina2G]

Why don't you just ground the black wire right at the passenger side sender unit and be done with it? It's the same wire as the one under the driver's side floor area, just at the sender end so you're grounding it there instead.

FYI: Sender wiring explanation:
2g AWD wiring:
On the stock setup for AWD there are 2 senders in the tank that are connected in series - one on drivers side, one on passenger side. The fuel gauge goes to the drivers side first in a yellow wire. This is the one if grounded should make the gauge read full (when key on - takes a minute). The drivers side then goes to the passenger side in a yellow/black wire. If grounded, the gauge will read something (between halfway and full) depending on the drivers side sender position. The passenger side then has a black wire to ground. If either this black wire is not grounded or the yellow/black between the 2 senders in not connected, the gauge will not work.

In addition to all this there are also 2 wires to run the fuel level low light. They are (on AWD) a yellow/blue from gauge to drivers side sender, and a yellow/black (different than above one so don't get confused) between the driver's and passenger's senders.

Thanks again for all your help with everyones fuel gauges, I've read your explanations alot of times and they're really helpful.

Just to clarify- the 2 ground wires in picture 1, are these deffinatley for the fuel level gauge? You said this is the very same black wire that is found in the passenger sending unit? The path the wire runs is from under the seat and goes to the trunk area and keyless module...how can this run the fuel gauge?

I guess the only reason it matters is what to do with the burnt up wire thats in place?

 

[luv2rallye]

Just to clarify- the 2 ground wires in picture 1, are these deffinatley for the fuel level gauge? You said this is the very same black wire that is found in the passenger sending unit? The path the wire runs is from under the seat and goes to the trunk area and keyless module...how can this run the fuel gauge?

I guess the only reason it matters is what to do with the burnt up wire thats in place?

- One of them is. The other must be the ground for door lock power relay 2 (for right side lock) which is behind the left rear passenger panel (beneath quarter glass).
- One of them yes.
- It is just the ground for the fuel guage. The signal is on a yellow wire.
- Just leave it. When you find something else whose ground is burnt up you can do the same thing for it.

 

[1Gina2G]

- One of them is. The other must be the ground for door lock power relay 2 (for right side lock) which is behind the left rear passenger panel (beneath quarter glass).
- One of them yes.
- It is just the ground for the fuel guage. The signal is on a yellow wire.
- Just leave it. When you find something else whose ground is burnt up you can do the same thing for it.

for the door lock, you're refering to the black pushbutton switch the door hits when it's closed right, for the passenger side? Because my passenger door light actualy does not work either, when doing a power drain test, the passenger door opening will not make the test light come on at all. It'd really be nice to kill 2 birds with one stone.

thing is, I've rewired the fuel pump assembley and my gauge assmbley did not work prior to the re-wire either. I remember there just being 1 black ground that gets soldered with all the new grounds in the rewire. I'll have to take another look at what's going on in the harness

 

[luv2rallye]

for the door lock, you're refering to the black pushbutton switch the door hits when it's closed right, for the passenger side? Because my passenger door light actualy does not work either, when doing a power drain test, the passenger door opening will not make the test light come on at all.

No. I'm refering to the ground for the door lock relay itself.
The passenger door light is a different circuit - your black pushbutton door switch is most likely bad (corroded or gunked up).

 

[1Gina2G]

okay so I don't usually use these kind of connectors, but I bought these kind that tap into the wires without making any cuts, adding a pigtails as well to the following wires at the passenger sending unit:

-the yellow/black wire that comes from the passenger unit
-the main black wire at the fuel pump assembley
-another black wire in the fuel pump connector

all together the gauge started slowly filling up, stopping at just above the 1/4 tank mark. then I grounded each wire indivdually, and found that only grounding the yellow/black wire did this.

after only seeing it go to 1/4 tank I thought the floater could be stuck this time, since I never could see the marks you were supposed to line up with. at the same time, it would have made since for it to be a little low, so I wanted to see if anything happend after some more gas, the gauge did not budge at all.

I also understand that the yellow/black wire is supposed to read in between halfway/full, but does it sound like I should keep the pigtailed ground for this wire connected? without it the gas gauge dies. Does it sound worth it to pull the fuel sending unit oncemore? or is there more wiring to check?

 

[luv2rallye]

It's sounding more and more like your sender(s) in the tank aren't working properly. Maybe stuck or bad or wrong ones for their resistance. Each should measure 2 ohms when in full position. In empty position drivers should measure 50 ohms and passenger 57 ohms. Re-measure them and check their movement again in the fuel if possible.

 

[1Gina2G]

It's sounding more and more like your sender(s) in the tank aren't working properly. Maybe stuck or bad or wrong ones for their resistance. Each should measure 2 ohms when in full position. In empty position drivers should measure 50 ohms and passenger 57 ohms. Re-measure them and check their movement again in the fuel if possible.

all 4 sending units (2 original, 2 new) I have check out with the ohms meter, the units were replaced due to kinked lines..checked by manualy moving the floater.

what I was wondering, is the gauge just reading a preset level from the yellow/black wire being grounded or is the floater piece just most likely stuck?

is there any links or guides on how to line up the fuel sending unit?

 

[luv2rallye]

Could the floater be hitting something or stuck when it's in the tank?

Grounding the yellow/black (with key on) means your just using the drivers side sender only so you should see dash gauge (after settling delay) read between halfway and full depending on the driver float position. Remember on the AWD there are 2 yellow/black - the other is the low fuel light.

The dash gauge reading full when you grounded the all yellow tells me everything from the sender forward is working correct. So problem is either in sender or wiring between them or to their ground.

Not sure - you'll have to search.