About to give up

My 1992 Cadillac sedan deville has had a new battery and starter put in, as well as a different gas tank ( used, but no holes!) will start after I put a charge on it, but as soon as you turn the car off, it only clicks. Somehow losing charge. Can anyone give me some inexpensive advice?

Check the charging system.

Take a volt/ohm meter and set to read 20 VDC. Place the probes on the battery and see if the battery reads 12.4-12.6 volts DC. If it does the battery is good. Start the engine and check the voltage again. It should read 13.4-14.6 volts DC. If it reads battery voltage and then drops off, there’s a problem with the charging system.

Tester

The battery is 2 weeks old and I just got the Starter today.

New battery, new starter. New alternator? Like I said, check the charging system.

Tester

What would I need to get to test that?

Go to a Sears store and get something like this, http://www.sears.com/brainydeal-lcd-digital-multimeter-ac-dc-ohm-volt-meter/p-SPM6312059002P?prdNo=10&blockNo=10&blockType=G10, or something cheaper.

Tester

It sounds like either you got a bad alternator or bad battery. I’d start by taking the battery and having it load tested. If the battery tests good have the charging system tested.

Alternator is most obvious suspect.
Google a video on how to test

Not new alt, but it tested good

Battery may be defective, internal short.

Could this be a starter solenoid going bad instead? Are the headlights still working and other electronics still active when the car just clicks?

Brand new starter

So does the battery seem to still run the electronics or is it truly dead?

Could it be a bad switch in the dash for the control of the starter? I’m not sure what year GM started using FETs inside the engine controller to control the starter solenoid but for years, and I believe 92 was still this way, the starter was activated by running brass/copper contacts over each other in a switch on the top of the steering column under the dash. These contacts would become burned just like the solenoid contacts over time and would be overlooked as needing replacement. Also the park/neutral safety switch has been seen to cause similar issues as the contacts in that switch are high current.

Two tests for these switches:
Turn the key to start, move the key slightly, very slowly back and forth in the start position, is there any spot that the car tries to turn over? If yes, the “ignition” switch is bad and needs replacement.

Second, turn the key to the start position. Slightly move the transmission selector forward and back in the park slot. If you get a position that it wants to start, replace the switch. Also try placing the car in neutral and trying to start. You can move the shifter also in that slot to try to find a sweet spot where the contacts allow current to flow. I have seen people create a 12AWG jumper wire with 2 spade contacts to temporarily bypass this switch as a test only. The connector plug has two large purple wires going into it on the top of the steering column near the floor/firewall of the car.

Either switch is not too difficult to replace if this is the problem.

I saw this problem on a caddy one, it too just had the battery replaced. The caddy in question had two cables going to the positive terminal on the battery and had a longer bolt to clamp the cables to the battery. It has a washer that goes between the two cable terminals to make sure the power was getting to the outer cable. The “battery technician” at sears lost the washer.

I saw this on a caddy once. (the new sight will not let firefox edit)

While you are checking things, check for a parasitic load that might be draining the battery…

Any answer on the battery? I had a similar problem a few years ago. Brand new battery. Installed in the parking lot so I could swap out the old one for recycle credit. Turn the key and click nothing. Three batteries later (all of which showed fully charged before I hooked them up) and the retailer conceded they occasionally get a ‘bad skid’ of batteries (probably dropped causing the plates to buckle and sulfate). Got my money back and went elsewhere. Problem solved.

Don’t ignore a bad battery. I bought a new battery a couple of years ago and it was bad from the start. The replacement battery only lasted about 6 months, too. FWIW, they were Bosch batteries. At least there was a warranty with them.