fuel light and gauge

2001 CHEVROLET BLAZER
115,000 MILES • 6 CYL • 4WD • AUTOMATIC
Avatar
GREEN6977
  • MEMBER
  • 25 POSTS
fuel gauge just stopped working on day. i checked the wire bundle. i couldn;t find any problems. what could be the problem.
Mar 8, 2011 at 6:14 PM
Advertisement
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
The most common failure is the sending unit in the tank. The best way to find out is to ground the purple wire at the tank and then turn the key on momentarily and the gauge should spike to full. If it does, the sender is bad.
Mar 8, 2011 at 6:56 PM
Avatar
JDL
  • CERTIFIED EXPERT
  • 16,098 POSTS
I'd take the sending unit connector loose from gas tank, use a resistor between proper terminals, turn key to on, see if gage reacts properly to resistor. You can get resistors at radio shack among other places, don't cost much. See the ohms spec in the chart below. You need to be sure and use the resistor on the proper terminals, at the fuel pump connector. Use more than one resistor high and low/full/empty. If the fuel gage reacts properly to the resistors, I think the problem is the sending unit in the gas tank.
Mar 8, 2011 at 7:01 PM
Advertisement
Avatar
JDL
  • CERTIFIED EXPERT
  • 16,098 POSTS
Hi Wrenchtech, didn't see you.
Mar 8, 2011 at 7:06 PM
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
No problem. The resister would be a good way to test it but he is going to have no idea what size to use or where to attach it.
Mar 8, 2011 at 7:11 PM
Avatar
JDL
  • CERTIFIED EXPERT
  • 16,098 POSTS
The resistor spec is in the diagram. resistor/ohms. Connect it between purple wire and black wire with white tracer. In the diagram. Sometimes I get ahead of myself. Have a good day.
Mar 8, 2011 at 7:29 PM
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
LOL, good info
Mar 8, 2011 at 7:40 PM