The battery in my '88 300E is being drained constantly. I measured (car not running) the following current drains at the fuse numbers listed below. Do these seem excessive for what is on them?


Fuse C 8.4 mA
Fuse 9 50 to 60 mA fluctuation

Thanks for any help.

That would put the amp hour drain at 1.7 amp-hours per day. It would take you about 2 months to drain the battery. If your battery is dead sooner than that, either it's not charging properly or the battery is shot.

I don't have a schematic, but those current drains are perhaps for the radio.

HTH

Joe

Fuse C is the alarm and a few other things, fuse 9 is the radio. The total draw borders on excessive, the radio circuit being most of it. As Joe pointed out this shouldn't take out a battery unless left sitting a long time. We usually get upset if the total current gets to 100ma, Although this amount is more common on later cars with many control units with memory.

Technically, you don't leak voltage, you leak current (flow of electrons).

P E H

Folks,

Thanks for the input. I wanted a second opinion on the amperage values as the car has been acting abnormally since it was hit (while parked) about a year ago.

I believe the battery was run down due to a broken trunk light switch. I got hit from the back and never noticed that the switch post was bent. I drive every day so the battery was charged back up daily. I went on vacation and it was dead when I came back. I recharged it. Then we had a nasty snow storm and it sat for a week. Dead again.

So, now I need a trunk light switch and a new battery.

BTW. P.E. was correct about leaking current not voltage. What can I say other than it was late. :(

Thanks again. This site has helped me more than once now.

Kmoran101,

One more technical nit: There is no such word as amperage but there is the word voltage. The correct word for a fuse rating is amperes which can be abbreviated amps. The word for electron flow is current with the unit in amps, milliamps, kiloamps, etc.

IE: This circuit is protected by a 5 ampere fuse.
The current used by the glow plugs is 80 amps.
This light bulb has a voltage rating of 120 volts.

If we use the correct technical terms it promotes better understanding.

P E H