BMW: 1997 E36 Gas Gauge malfunction

On Thu, 21 Aug 2003 20:37:08 -0400, "Mike B." <com> wrote:
 

Might be the sending unit is going to Heaven, might be the current source for
the meter (many dash systems use a 3 terminal regulator as a current source
for the fuel and temperature gages), but it could be as simple as corrosion in
the blades of the connector between the submerged sending unit and its
cable...

"Mike B." wrote:
 

I've had the fuel level sensor's fail twice on my car; however, both times the
symptom was a high fuel level reading - i.e. gauge says I have 1/2 tank of gas
and it takes 12 gallons to fill it instead of the 8 that it should.

Here's a possible test - fill the tank. Then pull the rear seat and measure the
resistance of the fuel sender units. There are two - one on the driver side is
a sending unit only, one on the passenger side is sending unit plus fuel pump.
Use the color of the connector on the driver's side to determine which is the
appropriate connector on the passenger side.

Measure the resistance of both sending units - should be 250 ohms, each, with a
full tank. If these are ok, and your gauge is incorrect, then there must be
some other fault - ground connection or something. If the sending units do not
measure correctly, then you've found your problem.

I recently pulled the combo sender/pump unit on my 97 328 to fix it. Not really
hard - if - you can get the large collar off. I cut a piece of aluminum flat
stock to use as a tool. Run the gas down to half a tank, or less, do it
outside, and don't smoke.

Frank