no start please help
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 34
Likes: 0
no start please help
new battery, says 12 volts, try to start then in like 4 seconds goes to like 7, wont start, new plugs, wires, been through 3 batteries, disconnected power seats various lights, radio, dont know what or how batt is draining. tested to see if fuses blow none did. anybody know whats causing this its an 85 vette 4+3
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
hot can you give a better description of your starting procedure? Does the starter engage? Does the engine turn over? Can you rotate the engine by hand? If you are taking a fully charged battery to almost discharged in 4 seconds that is an explosion. You can weld with a battery for 4 seconds. More data please.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You can tell the state of charge by measuring the no load battery terminal voltage. 12.0 volts (sounds like you) and below, discharged, charge your battery up at least overnight with a battery charger! 12.9 volts and above, fully charged and linear in between. The dash voltmeter reads low if the engine is not running. Do not use the alternator to charge a dead battery unless you like buying new alternators.
Remove the neg batt cable and connect an ammeter from the battery terminal to the neg cable lug. After the courtesy lights time out, ( close hood to turn off underhood lights too) reduce the full scale amps to read the leakage current. GM says leakage current should be less than 50 milliamps. My 87 measure 27 ma. and I have no battery problems. You can remove fuses one at a time and watch the ammeter to find the circuit with excess leakage current.
At night, look for underhood lights, vanity mirror lights, door map lights, center console light. Do you have a radar detector, GPS, CB, aftermarket alarm or radio or audio amplifier? Check em.
Remove the neg batt cable and connect an ammeter from the battery terminal to the neg cable lug. After the courtesy lights time out, ( close hood to turn off underhood lights too) reduce the full scale amps to read the leakage current. GM says leakage current should be less than 50 milliamps. My 87 measure 27 ma. and I have no battery problems. You can remove fuses one at a time and watch the ammeter to find the circuit with excess leakage current.
At night, look for underhood lights, vanity mirror lights, door map lights, center console light. Do you have a radar detector, GPS, CB, aftermarket alarm or radio or audio amplifier? Check em.
