More electrical problems...

[mike025]

Just when i thought i fixed the tail lamps (by disconnecting the underhood light) the fuse blew out again. Can anyone advise what else is on this circuit besides the underhood light and rear tail lamps?

In an unrelated issue....im trying to get the fuel gauge to work. I took the rubber boot off the gas tank door to expose the wires. There is power on the red wire, and i think the ground is ok. The gas gauge is pegged at full. PRior to reoving the red wire, the gauge was showing about 1/4.

On another note, to my amazement the build sheet was on top of the gas tank! I was able to get it out in one piece, but the years of sitting on the tank made the sheet unreadable. Talk about a roller-coaster ride!!

thanks for the help....Mike

 

[Vetsvette2002]

It would help to know what year you're asking about, no two are the same ya know.
You might want to invest in a full color laminated wiring diagram to see if Bubba has gotten into the wiring.

DonO

 

[Nut]

Sounds like a short to GND somewhere in the circuit. You absolutely need an accurate wiring diagram for your specific year C3. My fuel gauge bounces and it's a GND problem that I have never been able to track down in 15 years.

Good luck........... nut

 

[81kix]

Bob, your dog is really creeping me out. :W

 

[Mr. Chuck]

The 81 under hood light is hot all the time / no fuse; get pwr at the starter solenoid and have no common connection to the tail light circuit.
Regarding the fuel gage, fuel qty reading on the gage is determined by resistive balance between the internal resistance of the gage and the variable resistance value of the fuel sending unit as determined by the level of the fuel in the tank.
When you disconnected the red (pwr) from the sender, the gage should pegg and when the gage read 1/4, tells us the sender had a complete electrical path (some resistance) to ground. If the gage read 1/4 all the time, even when tank was full, then I would suspect the sending unit is stuck (failed) at one point. If this is the case you would need to pull the sending unit out of the tank for service / replacement.
The fuse blowing again, may very well mean that you have an intermittent short in you tail light or related circuits. The 20 amp fuse on the 81 tail light circuit provides powers to the Light switch, which inturn sends pwr to Instrument lights, the rear marker lights, the license plate lights and the tail / stop / Turn lights. A short in any one of these lights circuits would blow the fuse.
My shop manual shows a connector as part of the wiring harness on top of the fuel tank, location is not specified. Disconnecting it first may help to determine if short is between the fuse, Light switch and that point on the harness. An intermittent short sound like a wire pinched under a bracket during OEM car assy or some time when the tank was dropped or other area service work was done in the past. From my work experience, it often take quite a while for wire insulation to cold flow away from a point of compression (the pinch) to a time when the now exposed wire shorts to ground and blows the fuse.

 

[lone73]

Bob, your dog is really creeping me out. :W

No kiddin' !!
I thought it was just me thinkin' that...

Is it even a real dog ? That thing looks really weird.