Well now the gas gauge kinda works. Seems to get down to the half tank mark, hangs out there, and never goes down any farther. It was reading half a tank before I put 20.5 gallons of fuel into it. I know the thing has two sending units, checked the voltage coming from them at half tank, both seemed to be reading correctly and the ground in the back looks good and with the power probe, not reading any back voltage. Now I have had a hell of a time with ground problems up front so I was wondering if there is another ground that I am not aware of in the front. The ground lugs I had problems with were the main one (put new line in and cleaned up connection and put dielectric grease on it) and G104, which was to the radiator fans, turn signals, and I think cruise. Not really sure the wiring diagram on how the gauge works or anything so figured I would ask to see if there was something I was missing. I tried alldata and there isn't even the sending unit or gas gauge wiring diagram on it.

There is another problem I am having with the cluster and that is the speedo doesn't work but I THINK i know what that is. I replaced the PCM not to long ago and I think the chrysler guys didn't program something in correctly because I am also getting a code and the PCM and SKRIM module not flashed properly. Since it was replaced it has never worked. (replaced with Chrysler PCM also). With the speedo not working or the mileage and "mileage till empty", would that throw off the gas gauge? I assume not but stranger things have happened...Any info to give that show me some other places to look would be great.

 

Also, to clarify, when I filled it up after it reading half tank it not really being half tank, I let it go down to half a tank, and once it got there, I then checked the outputs of the sending units.

 

Does anyone know how the gas gauges work on these? Is there two sending units that send back to the PCM which goes to the gauge cluster? I'm thinking on saying screw it and just put an aftermarket gas gauge in a gauge pod and splice into the main line if there is one. Hopes someone could tell me if there is just one line or if there is two....and if anyone has attempted to do this before...

 

Unfortunately there are two fuel pumps, this vehicle has what is called a saddle tank. I own a 2007 Pacifica, and I have spent over a thousand dollars just trying to get this problem fixed. My far tank is basically still not even in use so I pretty much have to 20 dollar my tank to death. Wish someone would figure this out, or if it's a glitch in the vehicle, do a recall in the tank. My gauge goes haywire too, it's crazy, I'm as lost as you are!