Battery drains overnight (twice.) `89 Accord Honda

Sometimes intermittent battery drain with the engine off can drive you nuts.

Simple reasons are lights (glove compartment, trunk, etc) that may not always turn off when they should, relays that lock on when they shouldnt.

Since it doesnt always happen, it can be hard to find.

You can

-buy a battery disconnect, and decouple the battery every night. It works but is a PITA

-remove a different fuse every night, until you find the circuit that is offending. (Some circuits are perhaps on fusible links, not fuses) Then start down the circuit, eliminate branches as you go.

This happened to me on an 89 Buick Regal. I finally found it (whereas a dealership or independent mechanic might have given up, or at least charged me a ton) by the method mentioned above. The item causing the problem was a relay which activated the seat belt retractors...in the cold of the night, and even then only occasionally. It was enough to give me a flat battery every morning until the case was solved.

You could also stick an ammeter in the line with the battery and troubleshoot without all the waiting. You can wriggle connectors and fuses to your hearts content while watching the meter.

just my .02

It is a good idea, and I have done it this way too. If the drain is only intermittent, then you can wait a long time to see the problem. Hours sometimes.

Sometimes the xxxing intermittent is so difficult to find that you have to take the previously mentioned procedure.

on our old 88 Accord, the fault was the flip lights motor was always turned on even the car was off causing the battery to drain out.

Hi Sam,

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Kindest regards,

BiLL.......