O/T Using a 9v battery during battery swap

jCarroll · Mar 6, 2009

I read of using a 9v battery plugged into the cigarette lighter (aka power plug) while you disconnect the main battery to retain radio, computer data, etc.

Anybody confirm this technique? My gas gage went to the underside of the peg the last time I disconnected my battery - don't want to redo that fix.

Doug in Illinois · Mar 6, 2009

I have heard of that, but have no personal experience with it. I do know my car and maybe the pickup need to have the key to running position for the lighter to work. That makes me nervous, as I think a spark could do serious damage with key on. A lot of the newer cars have posts to hook jumper cables to away from the battery. I would just hook up jumper cables to them. On the older cars I would hook the + to the far end of the + cable and the - to any good ground. But, then again, on the older cars may not be necessary. Even my 2001 2500 Chevy was OK with battery out as long as you follow operator manual procedure, meaning make sure how to set the radio before you take battery out, etc. If you just unhook the battery, the radio thinks it has been stolen and won't come back up. DOUG

g mccool · Mar 6, 2009

Yes in fact NAPA & Car Care sell little adaptors that plug into the cig lighter on one end & on the other end is a plug in for a 9 volt battery. A lot of your car dealerships use these to retain memory in customers cars radios, clocks, ect. Gerald

glennster · Mar 6, 2009

yup, you can get em on any of the tool trucks. keeps the computer and radio memorys active. some vehicles, honda for example has a theft deterrent radio. if you disconnect the battery, the radio locks out. you need a code to re-activate it. other thing you can do is get a lighter plug for a jump box (jiffy jumper) to patch the jump box into the vehicle cig lighter or accessory plug.

bradk · Mar 6, 2009

Only ones I ever see that wrap the fuel gauge around is Buick Park Aves.

The 9v battery trick is used mainly to keep the radio presets and clock settings correct.

A cow magnet will bring the gas needle back home.

Goose · Mar 6, 2009

I bought one from Walmart and it didn't work, either on my Olds 88 or my wife's Chrysler T&C when I put new batteries in both of them last fall. 9 volts apparently isn't enough.

I did, however, put longer wires with allegator clips on the end on another lighter plug to clip onto a full size 12 V. battery if the occasion arises again.

O/T Using a 9v battery during battery swap

jCarroll

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Doug in Illinois

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g mccool

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glennster

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bradk

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Goose

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