We have a 1968 Oldsmobile 442 and the battery in discharging continually. We are in the process of installing a new Optima Red Top AGM Battery to see if it helps, but has anyone else has this problem? BTW - we don't have anything running except the clock on the dash.

Thanks for the help!

 

You have a parasitic drain somewhere. Pull the fuse to the clock and then disconnect the positive battery cable. See if you have a slight arch when you touch the battery cable to the battery. If you do, start pulling fuses until it disappears. Then you have found the culprit.

 

It would probably help if you give more details like is your previous battery really old, could have bad cells and wont charge properly, what's the volts on a full charge?, is your Alt charging properly etc, cant hurt to buy a new battery.

 

Also, what condition are your battery cables in? Crispy, burnt terminals with green oxidation and split jackets is a NO NO.

 

Speaking from 66 big car experience, my wiring colors may be off, but I believe the principle may help…

One culprit I’ve found along the way if it’s not the clock are the door jamb courtesy light switches. They physically move their orange and white wires every time you get in/out of the car.

In my big cars, these are the 2 pin plunger switches which I think were new in ‘66 because my 65 wiring harnesses had much larger diameter different switches.

As designed, there is very little clearance between those wires and the steel body which can cause them to ground when their insulation frays.

As noted above, pull the courtesy light fuse to test if this might be your problem.

Chris

 

With the battery charged remove both cables and let sit overnight. In the morning check the voltage for a drop. This may show it's the battery not the car