Need to identify a component not explicitly defined in the FM.

I'm rebuilding my 84 GSL-SE fuel level sensor. The component has a float and a barrel shaped sensor.

The FM shows the sensor and operating range (in ohms), but I am unable to find information on the barrel sensor.

I believe the barrel sensor is a 'low fuel' indicator and triggers the dash light.

A mech I spoke to said it is a 'temperature sensor'.

Does anyone have any information on the barrel sensor and it's operating range?

Fuel Level Sensor

Factory Manual Reference

 

It is indeed a low fuel sensor. If you look at the wiring diagram, the schematic indicates which wire color, on the connector side, is the fuel level and which is the low fuels dash light. it is also documented, somewhere, what the ohm values for the low fuel are.

 

Right on.👊🏾

Any background on testing range?

I would like to bench test it before I install.

 

Use a multimeter on ohms setting. Place once of the sending unit ground and the other on the fuel level and fuel low wires. I found the wire colors in the wiring diagram on the 1985 manual. You can do this before installing it. Move the sweep slowly and way for it to settle. Stop in the middle and on each end.

Fuel Gauge: Yellow wire - Empty: 103-117 Ohms, 1/2: 28.5-36.5 Ohms, Full: 1-5 Ohms

Fuel Level Low: Yellow/Blue full=6 ohms / 1/2=31.5 ohms / empty=80 ohms.

I've seen some conflicting values but have validated the Fuel Gauge ohms in the factory service manual just like you posted.

 

You don't reference 'how' to test the low fuel sensor, what medium should be used.

In this video (about 2/3rds of the way through) the guy just dips it in and out of a bowl of gas to test the low fuel sensor.

Does this make sense to you?

 

Yes - that makes sense.