Is 11.8 volts enough to start the car?

[Edmond]

The car wouldn't start this morning. Actually, it hasn't started on the first try for a week or so now but I haven't been able to get around to checking it out.

I don't think it's the battery because I jumped it to our LT1 Roadmaster and tried with the same result, wouldn't start. I'm thinking that it's not the battery, it's the starter.

Am I right?

Once I get it started (when I did manage to start it a few days ago), the voltage would jump up to the upper 13's right after it started.

 

[bradfordsvettes]

11.8 volts may be border line in my book should be well over 12 volts the best thing to do is load test it by the specs on the battery. if you are having a problem even with a jump and you had good connections your starter may be on the way out .it could have been damaged if the battey did not have enough amps to crank properly only my 2 cents steve

 

[mike weyman]

did you let the running car charge the sick car for a while before starting?or did you try it right away.a real dead battery will take a while to get enough power to turn over. mike
p.s. an alternator is only to maintain charge, you can damage the good car by trying to charge a battery, thats what battery chargers are for.I'm not being a smart a$$ , my buddy ruined his brand new alternator by not charging the battery before startup.

 

[vettenick]

You're not getting off easy on this one. Make sure that you're getting battery voltage down at the starter solenoid when you're cranking first. Your problem could be a bad cable or connection, including a bad ground cable/connection. Or...it could even be an ignition switch problem.
Good luck!

 

[tnovot]

no start

I agree with Mike and Vettenick. I once had a battery with such a bad internal short that jumping didn't even work.
You checked the battery connections, right? I'd check everything else before changing the starter.
If everything else checks out, you can remove the starter and have it tested at most auto parts places before laying out $ to buy a new/reman unit.

 

[bradfordsvettes]

mike is absolutly right about trying to charge a dead battery with the alt it will burn it out these alts are run on the ragged edge with no room for extra draw .a dead battery will max out the charge rate and smoke it for sure steve

 

[Gerry]

is 11.8 volts enough

If you can get the car to auto zone they will check out the battery and alternater for free. As others here have said the connections, cables, battery, alternater and starter could all be culpable. A bad battery will not take a charge and could cause further damage so pull it out and get it checked and then take it from there. Once you have a good battery you should pull 13.5 -14.5 volts when running, check cables and connections and clean everything. You should be able to find the problem before buying anything then buy what is needed. Good luck.

Best regards,
Gerry

 

[Edmond]

When I did get the car started, it was running around 13.8 or so. I'm going to take the starter off and have someone take a look at it.

I was told about some places where they can rebuild the starter for you. Anyone know of a good place?

 

[3sacrwd]

Good luck with the starter...They are a real Pain in the A$$ to take out and put back in.....Hopefully that is the problem and you won't have to spend alot of time chasing ignition problems. Take the advice and have your battery fully charged prior to starting. I ran through a few "lifetime" alternators by not having a fully charged battery. Good luck, let us know what the problem turned out to be.

 

[Gerry]

is 11.8 volts enough

If indeed the starter is a pain to remove you should check it while still in the car by jumping past the ignition directly to the starter from a good battery. Starters are just motors and if it works intermittantly then it usually is a dead spot on the armature or a solenoid problem. We used to hit them with a hammer to get them to start when that was the problem back a long time ago. Just make sure all connections are clean and well connected before doing work that may not have to be done. If you do need the starter rebuilt ask someone in the corvette club in your area to recommend a good rebuilder. Good luck.

Best regards,
Gerry

 

[scarbro2k]

Yep ! You can definitely screw a good alternator over if the
battery isn't at 12.5VDC. Once maybe twice and then the
diodes in the alternator blow. Generally a battery is good
for 2-3 years. Less if you are in really extreme climates.
Replace the battery if it is 30-months or older.
There are some alternators out there that can hack the
amperage needed to bring a down battery up. I've seen
them used as ARC welders at 4X4 rock climbing, mud
wallowing, cliff jumping competitions. Cheap is not a word
used in describing that class of alternators.