Fuel Tank Problem

[LastBattle]

 

I have a 1987 Sierra Half-Ton 4x4. Both tanks have fuel. The fuel switch on the dash has power to both sides and works. The engine only runs on the "left" side. When I switch to the "right" tank, it does not switch and the fuel contines to come from the "left" tank.

 

 

The fuel gauge does not change when I switch between the two. Even when one has less fuel, it does not read right side.

 

Suggestions Please...

 

Thank you,

 

Bob

[GM-Tech]

Wow, I had a hard time figuring those systems out even when they were currently in use. Shematics and information was always slim. I couldn't even guess at this point.

[Mr. Smith]

 

I have a 1987 Sierra Half-Ton 4x4.  Both tanks have fuel.  The fuel switch on the dash has power to both sides and works.  The engine only runs on the "left" side.  When I switch to the  "right" tank, it does not switch and the fuel contines to come from the "left" tank.

 

 

The fuel gauge does not change when I switch between the two.  Even when one has less fuel, it does not read right side.

 

Suggestions Please...

 

Thank you,

 

Bob

 

<{POST_SNAPBACK}>

 

 

 

I thought those trucks used an electrical valve to swap between the tanks. Have you troubleshot power to the valve?