Help Me Please! New Battery, New Alternator, No Charge!

[weskane]

so i have a 1992 SC300 and a few weeks back my battery light started coming on, then my alternator went out and i replaced both battery and alternator,

so now if i jump the car off it runs great but after i turn it off it only holds a charge for 20 or 30mins max, i checked the ground on the battery with a voltage meter and its fine too...

what should i do next?

thanks

[eatingupblacktop]

Sounds like you have either a parasitic drain on the batt, the batt has an internal short that's causing the discharge, the terminals are dirty or not tight enough for good contact, or your alt output might be too low to recharge the batt enough for a restart. With the everything in the car turned off, check what kind of draw is coming off the batt. If it's low, then take the batt in for a load test. Do a load test on the alt as well.

[weskane]

Sounds like you have either a parasitic drain on the batt, the batt has an internal short that's causing the discharge, the terminals are dirty or not tight enough for good contact, or your alt output might be too low to recharge the batt enough for a restart. With the everything in the car turned off, check what kind of draw is coming off the batt. If it's low, then take the batt in for a load test. Do a load test on the alt as well.

im gettin 14 or so while on and drops to 12 with the car off then slowly drains...

where would i look for the drain? fuse box?

[eatingupblacktop]

You need to check the current draw from the batt not the voltage to make sure it's an outside drain and not an internal short in the batt. Or disconnect the batt and fully charge it. Measure the voltage at full charge and again 30 minutes later. If the voltage has dropped, the batt is defective. If not, you can start isolating the different components that would cause a drain heavy enough to discharge the batt. Start with unplugging high amp fuses/relays one by one and checking the draw each time.

[weskane]

thanks, ill get on that tomorrow