Fuel gauge dead?

[BigBlockPaulie]

Hi guys, just installed a new fuel pump assembly from airtex and fuel gauge still doesn't read anything...
The car is a 2004 and has 150k, i did the pump as well to fix the fuel gauge but it still reads under empty, when I first got the car it worked but would drop to empty, then it just stayed on empty now for a year. I don't see a fuse listed for it either...

stumped!

 

[BigBlockPaulie]

Does anyone have a fix? What else can I check? Thanks

 

[Spriteman]

The fuel level sender sends a voltage to the PCM to let it know the fuel level which in turn sends an appropriate voltage to the cluster gauge to display.

As long as the fuel pump and cluster are working that means the appropriate fuses are good.

Since you have just installed a new fuel pump I would start looking at the gauge as being bad on the cluster although some have reported that the fuel pump sender units from some overseas manufacturers have failed on install.

You'll have to pull the cluster and put a meter on the connector at the fuel level pin to test whether it's even getting a voltage from the PCM.

 

[BigBlockPaulie]

Alright, thanks Spriteman. I figured the PCM is getting a voltage ok because I still get how many miles I have left on the tank of gas. I had the same fuel gauge problem on my deville, but just watched how many miles I had left, this car is I want to have working.
How do I check the gauge? Or how do I get the dash off? I'm a big guy, there's no under the dash, ha ha, have to get a grandson😱

 

[DonP]

If the DIC gives correct fuel information, the sender in the tank is most likely OK.

The fuel gauge pointer is moved by a small stepper/servo motor. The originals are prone to failure. The servo motor can be replaced but that involves removing the gauge cluster, taking it apart, and doing some PC board soldering. Not difficult if you have electronics technician skills. In my case it was the speedometer motor that failed, but went through a period of erratic readings first. The temp gauge and tach also use the same motor. GM went through several redesigns on this part. This is a likely source of the problem, but not 100% guaranteed.

This was common to many GM models in the 2003-2006 range. You can find sources of the stepper/servo motor on-line and EBay, and you can find folks who will do the repair for you. I ordered mine servos from www.speedometerrepairguy.com back in June 2011. He also does full repair.

 

[Spriteman]

Depending on how much the repair cost you may want to just go down to your local salvage yard and pick up a used cluster and go from there. Check out www.car-part.com and type in your zipcode and it will find the place that closest to you with the part.

 

[BigBlockPaulie]

Thank you DonP, that sounds exactly right, it just clicked in my head, my tach did some weird readings last week out of the blue, that's probably what's going on in my case. Does the dash come off at you or do you have to get underneath? I ask cause I don't have a chiltons

 

[DonP]

Could be more thatn one stepper is going bad, or a flakey conenctor perhaps.
There is another recent thread here that has a description of how to remove the gauge cluster.
http://buickforums.com/forums/threads/35369-dash-removal.
It may help.

For not much more than a Haynes or Chiltons you can subscribe to: alldatadiy.com and get what amounts to an on-line FSM plus FSBs.

 

[BigBlockPaulie]

Wow, thanks for great help guys, now I can do something with this info.
DonP the links are the most helpful.

I took this 04 in the tranny shop last night to R&R the transmission. It's been fade and bang shifting last week alot. Well it's got 150+ miles, been a great car. I bought it two or three years ago. I'm getting them to do rear main and oil pan gasket. Last month I replaced the front A-arms complete and tie-rods. It's a beautiful car, I still get compliments, so I don't mind keeping ($$$) it nice, but it's eating up my 69 el camino toy money.


www.flickr.com/photos/496elcamino/

 

[BigBlockPaulie]

Just an update, watched the removal videos and ordered the stepper kit with bulbs, waiting for them to get here Thursday, hope to do them before the Daytona Turkey Run.

 

[BigBlockPaulie]

Hey, the parts came yesterday, today I got home earlier and dug into the dash. I'm glad I watched the videos DonP I worked out cluster and opened it up. Unsoldered and replaced each, one at a time. Changed the bulbs, actually they where harder for me being hard to see. Put it all back together and worked it back into the dash, turned on the key and got nothing took it back out and one of the main plugs moved. The left side was tight and that's the one that I couldn't get to go in then I remembered the left end dash pad screw, taking that out gave me the wiggle room to lift up the pad and then the cluster went straight in without a fight and the plugs went right in and the cluster clicked into place, I tried the key and all the gauges jumped to attention😛 ! To anybody doing this don't forget that left end dash pad screw, you need that half inch of lift it gives you, button it up and enjoy. After the front end rebuild, transmission, fuel pump assembly, getting that little gas gauge to work is the icing on the cake!!!

 

[DonP]

Congratulations!
Celebrate with a cold one (or maybe two - its Friday)!