Battery losing charge
#1
Battery losing charge
68 442 convertible, 455, Th400, no AC Ext. regulated. So, I got stuck at the gas station Thursday night. Went to start it and nothing. I did notice it sounding weak the start before. I was able to jump it and get home. I put the battery on a slow charge for 24 hrs. Battery was @ 12.86 volts on the DMM. with the car off. I turned the car on and I was still getting 12.6. Took it for a couple short rides. check voltage with car off, 12.7, 12.5, 12.3. Going down each time. I think with the Car running I should have 14 volts+-. Also did a parasitic drain test and that passed well. Thanks Vintage Chief for posting that. I have an extra alt and regulator but don't want to change it out unless needed. An opinion on where to start would be helpful. Thanks. Greg
#4
Greg - As Jeff (Sugar Bear) suggested measure voltage at the battery w/ car running, all accessories OFF (e.g. AC, lights, radio, heater, etc.) & note total voltage being delivered at the battery from the ALT. I don't recall/know which ALT was stock/OEM for a 1968 442. Nearly certain it was delivered w/ and external VR, but the 442 I believe received the bigger/beefier ALT. In any case, the ALT may have been changed during the past 50+ years; therefore, validate what ALT you have as Jeff suggested, possible it's been converted to an ALT w/ internal VR. Which, in that case it's possible to suspect a leaking diode w/in the ALT. Get the total voltage measured at the battery w/ car running first.
#7
#8
OK, Battery is about a year and a half old. I'll need to bring it in for a test. Being at 12.8 after charging I was thinking its probably ok. Will check it though. Just started it up and its at 12.3 running. 12.4 with car off. Been getting these same readings all day. Slowly dropping. Just to clear this up. there is not of original in this car. I was saying it has a stock style regulator not solid state. Alt is a 1100843. 71 rebuilt.
#13
You can test the charging system to rule out the VR by following post #9. That is a 61 amp output externally regulated alternator.
The wiring has been redone, it looks a nice clean wiring repair sans original plugs.
The wiring has been redone, it looks a nice clean wiring repair sans original plugs.
#30
If the V doesn't come up when jumped with idle increased AND we assume the wiring is good AND the battery is fully charged, the alternator is weak.
We cannot at home test the VR without a solid alternator output so we don't know if it is good or bad.
We cannot at home test the VR without a solid alternator output so we don't know if it is good or bad.
#38
Confirmed 12.3. Thank you for taking time on your Sat. Night to walk me through this. Don't know how many threads I've read that just never came to a conclusion. Enjoy the rest of your weekend and I'll follow up when fixed.
#39
You are welcome.
Here is what we KNOW, the VR is bad AND the alternator is producing sufficient V. We have also mostly ruled out wiring from testing from the alt directly and through wire harness at the VR.
Here is what we DO NOT know and have to assume for now that is ok, we don't have the equipment to test the alternator amperage output but it is probably fine.
Replace the VR, go quality on the part, fully recharge the battery, raise the idle and retest V at the alt output stud and across the battery.
Here is what we KNOW, the VR is bad AND the alternator is producing sufficient V. We have also mostly ruled out wiring from testing from the alt directly and through wire harness at the VR.
Here is what we DO NOT know and have to assume for now that is ok, we don't have the equipment to test the alternator amperage output but it is probably fine.
Replace the VR, go quality on the part, fully recharge the battery, raise the idle and retest V at the alt output stud and across the battery.