The gas gauge on my 71' El Camino isnt working anymore.... the guy i bought the car from had it sitting for about 6-7 months and now it doesnt work anymore.... Do I have to drop the tank to fix this? New sending unit maybe?


Thanks.

Yes, the sender goes in the top of the tank.

Is the guage reading over full?....If so, the ground to the sender has probably rusted off. Check that out 1st.

__________________
Home Handyman Forum I Shade Tree Mechanic Forum

Recently with my 86 olds, The gas gauge stopped working, so I checked the ground, worked for a little while after I repaired it. Next I dropped the tank and replaced the sending unit. Gauge still read the same, quarter tank for full tank. I did the test as you can read how to do on this site in the knowledge base, test said sending unit. I got word the gauge has a resistance block on the rear, so I removed the cluster and checked it out, went online and found a site called fix a gauge. I ordered there repair kit for like 8 bucks, gauge works great since.

No the gauge is reading on empty...

My experience was that a weak/bad ground showed an empty tank. A disconnected wire to the sender showed a full tank.

So do I check this on the fuel tank itself or behind the gauge? sorry for the dumb questions.... im a newbie to this.

Sending unit.It goes in the tank on the very top.Wise to syphon all the fuel out that you can.Those tanks can be heavy and are awkward when full.

Unhook the sending unit and ground the wire to the gauge, it should peg out. If it dosn't do anything , the gauge is bad. If it does, check the ground. The float could be stuck, caused by varnish from old gas. I've seen this happen several times on cars that have set a long time. Last, the unit itself could be bad, remove it from the tank, hook it up, ground and positive wire, and move the float up and down, watch the gauge........

Troy

That is similar to what happened on my 85 ElCaminoi TC.The wire rubbed thru on the frame rail where it runs back to the tank and sent the signal to ground.I started at the tank thopugh since that is the best starting point.



We still do not know if the reading is full or empty. Where is the gauge reading SS?

The gauge is on empty.

It doesn`t matter where the gauge reads, the gauge still could be bad, as well could the sending unit. It`s not uncommon for GM gauges to go bad. I told you what I told you out of my own experience, rather or not you want to follow up on what I said is up to you. When I grounded out the gauge, it read properly, the test said it was the sending unit, I replaced the sending unit and the gauge still read off, so you can`t put total faith in the testing procedure regardless of where the gauge reads.

You can test the gauge with the tank down and unit out.Get a multi-meter and set it to the Ohms.Measure to see if you have resistance when you move the float arm.If there is reistance changes the problem is going to be in the wiring.Do not ever just assume something is bad if it involves the electrical system.Troubleshootiing steps are the only way to go.Replacing parts without knowing for sure can get way to expensive.Most places will not allow you to return an electrical component onc eit has been installed.