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97 Regal GS Fuel Sending Unit Problem

2K views 6 replies 4 participants last post by  anthony 
#1 ·
Hey 3800 Fans,
I have a little problem, my Regal's fuel gauge is almost always on empty (or sometimes on full). I've searched around a bit, and think that it's a problem with the fuel sending unit. Just want to double check before I either drop the tank or open the trunk access panel to replace it. Any other suggestions on why it is doing this would be appreciated, as would step by step directions on how to do said suggestions. Thanks in advance!
 
#2 ·
Might be worth the trouble to pull the cluster and make sure the wire is nice and tight.
I'm not sure of a known issue with those in particular (I don't work on them much) but someone will chime in.

As a general rule though,before I dropped a tank I would for sure narrow it down to an issue in the sending unit.

Alot of other gm vehicles i've had similar problems with were generally either a cluster issue or the contact on the cartridge itself just needs bent a little onto the resistor board a bit more or less.
But I've not had the issue on a car,mainly trucks and fiero's.
The fiero's it was from the sending unit AND the cluster AND the wiring AND then the sending unit again.
 
#4 ·
Thanks for the suggestions. I've got the access panel to the sending unit off, and the wire disconnected. Can anyone tell me what/how I'm supposed to check the voltages? I would really like to narrow it down before I pull it out, as it seems like a lot of work, and I don't want to do it for nothing.
 
#5 ·
Connect a DVOM to the purple wire at the sender and the other lead to ground. You will be looking at raw sender voltage. The IPC and PCM's use a filter on this wire.
Look at the voltage on the purple wire. Say it is 1.75 volts and when the gauge jump to full or empty the volage will jump to either 5 volts or 0 volts.
 
#6 ·
I don't currently have a digital vom, but I did test it with an analog. I can't recall the results, but after cleaning and disconnecting, then reconnecting the cable to the sending unit a few times, the gauge is now on full. I doubt that the tank is, since it has been 64 miles since the last fill. Time will tell, but I won't be driving it any time soon as the dash is currently torn apart. I'll keep this thread updated with any new results, along with the voltage once I find it out. Thanks again to you Caleditor!
 
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