smparr

My 1970 98 has a bad fuel gauge and I picked up a parted out gauge cluster for it. Is there a way to bench test the gauge without tearing my dash apart only to find out this one doesn't work either.

Thanks,
Steve

jaunty75

What are the exact symptoms? What does the fuel gauge read when the ignition is on and there is a known quantity of fuel in the tank? In short, how do you KNOW that the problem is the dash gauge and not the tank sending unit, which, 99 times out of 100, is the cause of a malfunctioning fuel gauge?

jaunty75

Here's a good, recent thread regarding a fuel gauge problem in a '73 98.

https://classicoldsmobile.com/forums...-right-146663/

smparr

The fuel gauge has been stuck at 3/4 since I bought it five years ago. It probably has been stuck much longer. When I disconnect the brown wire in the trunk it goes past F as it should but when I ground the wire it only goes to 1/2 instead of E. I did a resistance check on the sender end by putting the one lead on the trunk plug (sender end) and the other to ground and I get zero ohms.

jaunty75

This shows that you do have a problem with the dash gauge. There may be something (rust, who knows what) preventing the needle from moving freely across the dial. I don't think you have any choice but to take it apart and check. You mentioned that you have another gauge, and you wanted to test it before installing it. I would think you test it the same way as you tested the original gauge.

Either there is a short or the float is stuck in the fully down position, which is where it would be if the tank were empty.

If I were you, I would just re-do the entire fuel system. Take down the tank, remove the sender, and clean the tank or have it cleaned. There are rubber lines that connect the sending unit pipes to the hard steel fuel lines coming from the front of the car. I would think that, given the age of the car, these are crispy as well and should be replaced. Get a new sending unit and install it before you reinstall the tank. Then work on the front end of the system. Remove the old gauge and clean it if it can be cleaned, or replace it.

oldcutlass

Check the grounds for the gauge/cluster or it could be the resister on the back of the gauge is bad.

smparr

Does anyone know how you're supposed to release the side latches on the cluster connector of a 1970 98LS. I removed the pad/bezel and was able to get the speedo cable to release. I removed the crotch cooler vent and was able to snake my hand up to the connector. I cannot put enough pressure on the connector to release it once I feel it. You can't pull the cluster forward enough to tilt it down to reach it either. I just want to replace the fuel gauge with one from another car. I did the electrical test on the sender and everything points to a bad gauge. Help!!!

Steve