Float charger question

[AirKuhl]

I have a Porsche branded float charger (trickle charger) that I used with my previous 997. It plugged into the cigarette lighter so it was very convenient and also has a display that shows me whether or not the charger is working and if the battery is topped off.

In my newly acquired '74 the lighter is out of the circuit when the car is off so I can't use my charger. Any ideas on how to rewire the lighter so that it's live when the car is off so that I can use my charger? Any downsides to that approach that I should be aware of?

Thanks,
--Pete

[911pcars]

Originally Posted by AirKuhl

I have a Porsche branded float charger (trickle charger) that I used with my previous 997. It plugged into the cigarette lighter so it was very convenient and also has a display that shows me whether or not the charger is working and if the battery is topped off.

In my newly acquired '74 the lighter is out of the circuit when the car is off so I can't use my charger. Any ideas on how to rewire the lighter so that it's live when the car is off so that I can use my charger? Any downsides to that approach that I should be aware of?

Thanks,
--Pete

One way is to cut off the cig. lighter connector, then connect the charger permanently to the electrical system or temporarily with alligator clamps to the battery posts like other aftermarket chargers. All this can be hidden neatly in the trunk.

if you want to keep the indicator lights on the charger connector, find a cig. lighter receptacle-to-pigtail adapter and attach the pigtail ends to the fusebox or battery accordingly.

I suggest the permanent connection since the plan is to charge while the car sits. With the hood open, you can easily observe the state of charge.

With a voltmeter, locate and identify a fuse position (unused preferably) that remains "hot" when the ignition is OFF (both sides of fuse will have source voltage). Connect the positive charger wire there (downstream from the fuse for circuit protection). Connect the negative charger lead (probably black wire) to a good ground. The factory battery ground location on the chassis is close by and convenient. Use lock ties and hide extraneous wires to maintain neatness.

Of course, you could rewire the factory cig. lighter receptacle as well, but I'd leave the wiring at factory specs. - easier for later troubleshooting, next owner, etc. I'd suggest one of the alternate options.

Hope this helps,
Sherwood

[AirKuhl]

Excellent advice, thanks.

[nineball]

Cigarette Lighter Socket | Parts-Express.com