My Cutlass had not been cranked for several weeks and today on a beautiful 75 degree day I tried to crank it after spraying carb with starting fluid. The engine stated for a brief second and stalled immediately. Then when I quickly tried to crank it- nothing is working. No horn, headlights, no lights on instrument panel, no door buzzer, no sound when I turn the ignition key. I hooked up my Battery Tender jr. on my Interstate battery to charge it since car has been sitting so long. The charger light was flashing green immediately and manual says that indicates battery is at least 80% charged. I have not driven it very often and just sits in the enclosed garage, especially since I started having brake problems a few months ago. But for 30 years of hanging in my garage and only cranked and driven once a month or so, it usually cranks right up after using starter fluid. I am not sure where to start trying to diagnose why all the electricals are dead. Any help will be much appreciated.

 

clean your battery terminals with a wire brush, one may be loose

 

Or corroded. Follow the the voltage and look for where it goes away.

 

I would not put faith in the flashing green lights on the Battery Tender Jr. as an indication of having achieved at least an 80% charge. You need to MEASURE the voltage of your battery with a digital multi meter (DMM). MEASURE the voltage of the battery when it is completely unhooked from the vehicle. A fully charged battery should read 12.6V. You should START your troubleshooting process (as others have already identified) with a fully charged 12.6V battery (measured and identified with a working DMM).

 

^^^THIS^^^

Use a battery charger besides that little Battery Tender Jr. to charge the battery. You can also remove the battery and take it to your local auto parts store to be charged if you don't have a charger at home.

 

A Battery Tender puts out only about 1 to 1.5 amps of charging current so it would take days to charge a very low battery.

I think your problem is dirty battery posts. Get one of these and clean both the post and the inside of the terminal clamp. Or a pocket knife can do it, the brush just does it quicker and more effectively.


Won't hurt to have this either. It's a battery load tester and will tell you the battery's state of charge. It can also test your charging system.



And here's something every old car owner should have. A multi-rate battery charger.

Most modern battery chargers are pretty much foolproof. They'll automatically shut off when the battery gets fully charged, will automatically adjust charging rate as the battery gets close to fully charged state, and often have polarity protection so it won't start if the (+) and (-) leads are reversed.

You can get all three at Harbor Freight and they'll work fine for an average old car guy. Any auto parts store should also have them, and you can sometimes find a decent working battery charger cheap at a yard sale or flea market.

 

Hi, new to sight, Based on started fine, and then absolutely nothing - not even a dash light or buzzer - kinda makes it total loss of voltage. I’d start with battery cable connections/cleaning & battery voltage check.

 

Most auto parts stores will also load test a battery for you if you bring it in.

 

Thanks for the feedback to my question. Since I had gotten a reading of 10.5 volts with my multimeter on the battery with and without being connected, as well as no luck with trying to jump start it by using the Engine Start on my Craftsman charger and finally realizing that my Interstate battery had just turned five years old, I purchased a new Intersate battery yesterday. Before installing the new battery, I cleaned the terminals on the original battery cables as recommended and due to not having been cleaned since I purchased the Cutlass new. I must say they were not nearly as corroded and dirty as the top posts on some of my other cars and truck. Well, the good news is that the engine cranked up without much effort! The headlights are much brighter and the door buzzer is "much" louder. The guy at Interstate Batteries told me he bet that the battery has a bad cell since I do not drive the car much and suggested I keep the battery hooked up to my battery tender.

Now I have to work on finding out why the back reservoir on the master cylinder was almost empty and brake light on. I had asked my long-time mechanic who I have used for ten years at least, if he would trouble shoot the problem. He told me that he was not interested in working on the Cutlass. It would tie up his lifts far too long and he needs high turnover and get repairs done. His shop does so much business that he said he could work on problems with my Lexus in six weeks. Thanks again for the help given on my battery issue.

 

My guess is the master cylinder is leaking into the brake booster. I had that happen 2x over the years. Unbolt the master cylinder, pull it forward away from the booster, and look for dampness.

 

Or a leaking wheel cylinder.

 

Troubleshooting/Diagnosing the brake issue might (probably will) be more involved than changing a dead battery.
(1) Do you intend to perform the troubleshooting/diagnostics yourself? If so, it is imperative you own the 1972 Chassis Service Manual (CSM).
(2) Does your vehicle have front/rear (drum/drum) or front/rear (disc/drum) brakes?

 

I reviewed several of your older threads/posts and note you have front/rear (disc/drum). Albeit, you have a brake combination valve assembly. The single reason your dash brake lamp is illuminating is because the Pressure Differential Valve (piston/rod) inside the combination valve has shifted "off-center" causing the brake switch to close the circuit and illuminate the dash brake warning light. Since you've had this condition (dash brake lamp illumination + low MC rear reservoir) in the past (with no corrective action to date) and it involves a significant safety feature on your vehicle, if you do not feel comfortable working on the brake system, I'd recommend you take your vehicle to an automotive service garage which specializes in brakes.

Correctly Reinstalling Master Cylinder Cover on 72 Cutlass

 

Yeah, I missed that one. Look at the inboard sides of the wheels for evidence of brake fluid leaking.

 

Thanks for the helpful feedback on my brake issue. Vintage Chief, your post reminded me that I have let this brake problem incubate for seven months. As much as I like to fix problems myself on the Cutlass, I think repIacing the master cylinder and booster would not be that difficult, after having watched several YouTube videos. I do have a 1972 chassis service manual, but having to possibly replace leaking wheel cylinders and/or brake hoses in my garage could be more challenging. I have priced the various parts to fix and update the various original components of my brake system, and my preference would be to purchase them from Fusick for about $450. Not many repair shops will use owner’s parts and use cheap foreign parts as well. With 193,000 miles on the Cutlass now and still wanting to sell it and the 40 year collection of new and restored OEM parts, it would probably be wiser to just find a brake specialist to make the car safe to drive and drive it more often.

 

As yet you do not know where the issue resides MC/Booster/brake line/cylinder, etc. A brake specialty shop should be able to address this for you quickly to resolve the issue. I would not suggest purchasing any new parts whatsoever until the issue/problem is first diagnosed satisfactorily. I commend you for making the best decision to seek a specialist. You’ll sleep much better.

 

I still have stiff brakes in spite of current brake issues. I did refill the rear reservoir last July, but have only driven it down the street and back a few times since. Would it be safe to drive the Cutlass for repairs, if repair shop is within 10 miles or should I have it towed? I guess it would be best to tow it and be safe and not sorry, as the old saying goes and be prepared to use the shop that quotes the best deal beforehand for various repair scenarios.

 

This is not hard to diagnose. Pull the rear tires and drums and look to see if you have any leaks. We all do these type of repairs in our own garages. Once you figure out where the leak is, then order the repair parts either on line or go to your local auto parts store. If you don't feel competent enough to repair this yourself then carefully drive the car to the repair shop that is 10 miles away since you have front brakes and good pedal.

 

Good advice from Eric if you have the ability to diagnose. I’d also drive it to the repair shop - worst case, be sure your Emergency Brake is working.