The International Cessna^® 170 Association

I was cleaning out some things in my grandpa's shop this weekend and found some of the original pieces from 8180A. The lighter was removed a long time ago, probably because of AD 79-08-03. I would like to reinstall it (with proper paperwork of course).

What would the recommended wire size and inline fuse e for the 12v lighter socket? I would like to use it to power my Garmin and charge my iPhone etc... I was thinking 16 or 18 gauge wire and a 5 amp fuse?

nippaero wrote:I was cleaning out some things in my grandpa's shop this weekend and found some of the original pieces from 8180A. The lighter was removed a long time ago, probably because of AD 79-08-03. I would like to reinstall it (with proper paperwork of course).

What would the recommended wire size and inline fuse e for the 12v lighter socket? I would like to use it to power my Garmin and charge my iPhone etc... I was thinking 16 or 18 gauge wire and a 5 amp fuse?

It's been a long time since I read that AD, but I seem to remember that if you're actually going install a working lighter, there was an alternate method of compliance by installing a specified wire size and fuse. If you're only going to charge portable electronics, then 18awg and a 5-amp fuse is probably good.

It specifies in the AD

The AD does not specify the rating. It just points to AC 43.13.

NOTE: For those installations reconnected in accordance with paragraph A 1 the proper rated circuit protection device to be used may be determined by consulting FAA Advisory Circular 43.13-1A.

The AD says:

To prevent an inflight electrical system failure, smoke in the cockpit, and/or fire in the wire bundle behind the instrument panel, accomplish the following:

A) Disconnect the wire, at the ammeter or at the electrical system bus as applicable, that connects the bus to the cigar lighter receptacle. (The wire is connected to either the bus side or equipment side of a circuit breaker or to the ammeter.) Following the disconnection of this wire either:

1) Reconnect the wire to the electrical bus by using an existing or newly installed circuit protection device that is properly rated to protect the wire gauge used for this circuit, or

2) Disconnect the wire from the lighter receptacle at the opposite end and remove it from the airplane, or

3) Protect the wire by insulating its disconnected end, fold this wire end back against the wire bundle in which it is routed and secure it to that bundle.

43.13 requires the following CB/fuse based on wire used. As Bruce says if your going to just use it for charging 18 wire and a 10A CB/fuse is fine, if you actually want to use it with the lighter than you may want to step up to 14 or 12 gauge wire and a 20A fuse.

I put mine back in with 12 gauge wire and a 25 amp breaker but that was serious overkill.
A 5 or 10 amp breaker with appropriately rated wire is fine for charging phones.
Keep in mind, if you try to use the lighter it will pop the breaker at 5 or even 10 amps.

Thanks guys. That was the same chart I was looking at. I have no intention of using the lighter. I thought 10A was a little overkill. Will go with 5A.

By the way, if your original unit has any corrosion or is not make good contact you can buy a replacement at any auto parts store for about $5. They fit perfectly, look exactly the same in the panel and have the modern push on connectors rather than the solder on connectors of the original. I had problems with my original with charging units not making good contact, so just bought a new shiny one.