New Guy, with issues...

[mrmcq]

So I recently picked up a 1990 Legacy L sedan from my grandfather who can't drive anymore. A little background on the vehicle: about 2 years ago it blew the coolant bypase line and my grandfather chose to drive his truck instead of getting the car fixed. It sat in his driveway for the last 2 years. I just purchased it from him for $1000 last week, in hopes of easy fixes to get it daily driver running, so I could save on gas. My current Daily is a 2003 Durango that gets around 11 mpg, Ouch! Anyways I have what I can is an electrical issue and I can't for the life of me figure it out.

Fuel gauge stays on Empty, pegged out at the bottom. I did some searching on the internet, pulled the single sending unit (fwd), cleaned the contacts with an eraser, reinstalled. After that I tried the "Jumper" method using a test light and a good ground. of the 3 wires that should be for gauge/light, I have green, black, and green with blue trace. The solid green when jumped + ignition on triggers the gas light to come on. The green/blue, does nothing, no light comes on (in test light) and needle doesn't move. To me this sounds like I'm not getting power to that wire. Can someone confirm if there should be power there when ignition is set to the on position? I really want the gauge to work as I have no idea how big or how much gas is in there.

I did find a wiring diagram but the wire colors don't match what the harness has. according to this diagram:
http://www.main.experiencetherave.com/s ... iagram.jpg
I should have a GL, G, B (assuming that's Green, Black, and Green/???) connector R77, this is odd because if I recall the plug is a 6 pin with only 5 wires installed, they are installed in the positions that would be R22. But of course those wire colors are completely off. Please help.

Also, checked fuses and all the fuses look good, (pulled and checked with flashlight/multimeter for continuity).

[Legacy777]

You'll find the diagrams for the 90 Legacy, including the fuel gauge wiring here.

http://www.main.experiencetherave.com/s ... agrams.zip


Looking at the diagram, those colors don't seem to match up with what you're describing. Where is the wiring that you're referring to, is it the connector that plugs into the fuel pump assembly?

[mrmcq]

You'll find the diagrams for the 90 Legacy, including the fuel gauge wiring here.

http://www.main.experiencetherave.com/s ... agrams.zip


Looking at the diagram, those colors don't seem to match up with what you're describing. Where is the wiring that you're referring to, is it the connector that plugs into the fuel pump assembly?

Exactly, its the wires on the pump connector.

[Legacy777]

Ok, I think I may know what's up. The colors indicated in the manual refer to the colors of the wire on the chassis side of the connector, not the side going to the fuel pump assembly. Connector R22 is the correct connector. There's five wires, two for the power & ground on the fuel pump, two for the fuel gauge, and one for the low fuel light.

Based on your description I would say the solid green wire is for the fuel light, which appears to be working. The other two wires are what goes to your fuel gauge. You need to check the resistance between those two wires. You should be between 2-5 ohms when the tank is full and around 92-95 ohms when the tank is empty. If you don't a reading that is between those values the fuel level sender is probably bad, and you'll need to get a new one. Don't recall the cost, I've had to replace both of them on Legacy since it's AWD and has two. Replacing it is pretty straight forward.