Fuel pump bulletin

VICTOR721

MEMBER
1996 CHEVROLET S-10
6 CYL
2WD
AUTOMATIC
140,000 MILES

I have a 96 chevy s10. I replaced the fuel pump and I noticed it had a bulletin to replace the harness connector. I originally noticed the colors were the same so I spliced them that way. Later I realized that the sending unit's pwr and gnd have been reversed. Now the gauge jumps passed full and stays there. The pump works and the truck starts. Could I have damaged the sending unit, is it defective, or is the problem somewhere else?

Tuesday, April 12th, 2011 AT 5:09 PM

2 Replies

HMAC300

MECHANIC
48,601 POSTS

You really woldn'tbe able to find out until you changed the wiresback correctly. It doesn't get fullvoltage, it is sent sporadically like off and on so I doubt you damaged it but you never know until you change it out.

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Tuesday, April 12th, 2011 AT 10:29 PM

DAVE'S BIG BACKYARD!

MECHANIC
262 POSTS

It sound like you have the sending unit part of the unit crossed. This only has like 5 or 6 volts and you should have power there when the key is on and as long as the key is on so it should be easy to find your hot wire. At the fuel pump sending unit, purple is voltage, black is ground. Did you correct the wiring? If you unplug the connector at fuel pump, turn key on, what is the gage reaction?

You can use a resistor at the connector sending unit wiring/purple wire. Radio shack sells resistors, don't cost much. Get a couple different sizes. 90 ohms, the gage should read full. 45ohms or less, the gage should react accordingly. If that checks out, check the connector itself. Next, I'd have to suspect the sending unit.

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Tuesday, April 12th, 2011 AT 11:37 PM