So, here I am again with another saga. This crap has to end so that I can get to the point of restoring this car instead of fixing previous owner issues. Car is beautiful, as is the 455 out of the 1970 GS. The inner fender on the pass side is a little rotted though and is where the battery tray sits. Now I do have the tray though. What he had before he sold it to me was put a new alternator on the car and put a new battery in. We are having issues where the car starts great. Wife drives it around, runs an errand, gets in, starts perfect. Runs another, then the battery is weak, starter clicks, but finally slowly turns the motor over to start, by the time she is at another stop, or comes home, she will shut it off and try to restart it and its just clicks. If I wait awhile and go back out, the car will be weak but start. I took the alternator back and got it exchanged anyway, as the previous owner SAID it was new, I did not have documentation of that, so I put a new one on. Voltage is charging fine. Battery voltage is great, even when it will not turn the starter or is weak to turn the starter. Here i think is my problem but do not know enough about how they work, even with the research i have done. Since the inner fender is almost shot in the battery compartment, he has the tray sitting in there and then has a bungee strap to keep the battery in place, strapped to bracing under the inner fender. The battery tilts a little to the outside of the car, so I assume that is why he put in an Super Start Platinum AGM Battery. I am thinking that the AGM battery is not providing enough Amps to turn this big motor consistantly even though the volts are there. Once it sits, maybe the battery is able to rest and regroup enough amps together to fire it? So my question is 3 fold: 1. do you believe that the AGM Battery is worth the money they want for them, or is this not a good application for the 72 Skylark? 2. How in the hell am I going to get this tray stabilized enough to sit level so that I can run a regular acid battery? I do not have a welder at my disposal and although, will change the inner fender at some point this winter, I want to be able to have the wife drive it till then. 3. Is this a known issue with that battery tray compartment getting rotted due to the old batteries venting?
(3) Yes, they all rot here. That’s why the right side patch panel exists. (2) I used a small 2x4 under a GTO tray (and a bungee) in a ‘68 for a long time. Regular battery, not AGM. (1) AGMs are way overrated in my opinion, and your problem sounds a lot more like a cable, ground, or timing problem than a battery problem.(It could be battery but if so it’s not that it’s AGM it’s just bad or defective). Do your cables have real ends or ‘permanary’ repair ends? Is the engine grounded to the firewall? What is your timing at when cranking? Patrick
Size of cables makes a big difference, charging wise depending on the negative side having a good connection and also battery that seem a fine on cold start and then late does what yours is doing is usually a dead cell in it. Replace cables with size #2, get a new battery with a cold crank of 700 or bigger, over 800 is optimal
It looks like they have real ends on them, like they were factory put on. Not sure about the engine to the firewall. The battery is grounded to the frame. I do not have the knowledge or tools to know how to do this. I used to remember my dad checking timing back in the day, but I do not have a timing light or the nohow to check it.
So the car was very slow starting the last time it started, after she ran constant errands, like i mentioned. The wife drove to have lunch with relatives and the slow starting was at 12:30. she drove around 10 minutes to lunch and was there till 2:10, and when she went out, the car popped off no problem. So, its as was said earlier, when it is cold or "cooled down" a bit, it fires no problem, but to stop, go in a store, or even to shut it off and restart right away, it either is slow cranking, or the starter will just click like it has no amperage to turn it over.
Cables should be #2 are best, #4 minimum. Next the way you describe it , sounds exactly what I have experienced several times with a bad cell Battery. If you take and test it they will tell you it’s good because they are auto parts counter cashiers at best, buy a new battery with over 780 cold cranking amps and replace those really small cables and then measure when it’s running should be 13.9V min. Not running should be over 12.2v. Anything under 12 and you have a problem.
You are right, the guy said battery is good. Seems to be an issue when the car is hot. Cold is not an issue.
I put "0" gauge cables on my car. Great investment. The next time it wont crank fast put the meter on the battery and see what it reads. Either the starter is bad or you have a connection issue.
I took and replaced the ground cable as the other one looked like it was pretty old and worn and i was having trouble getting a solid continuity reading from one end to the other. So far I have had good starts all around.
When I got my car (yikes..ten years ago) the battery cables looked "good". Turns out they had corroded inside the jackets. All new cables solved the same problems you are describing. I also had the same Battery rot. I ended up replacing the right inner fender,core support and battery tray. I have some thin rubber strips under the battery. I pull they battery once in a while to clean the tray and touch up any sketchy looking paint.
Heat will make a bad battery cable, wire, or connection issue worse. It sounds a lot like you had a bad battery cable, cables, or connection. When corrosion develops in the cables or at the connection points, it generates heat there due to resistance. Add the heat from normal engine compartment temperatures to it and it makes the issues worse. I would think that is why the car would turn over easier, after it cooled down. I try to make it a point to clean my battery terminals and cable connections every time I change the oil in all of my vehicles (motorcycles too). Sounds like you fixed the problem.
