The International Cessna^® 170 Association

What amp rating is the cigar lighter fuse. My inline fuse holder is missing the fuse, but I now want to use it for my new voltmeter(per the advice in the other thread).

The AD only states: "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"

Thanks!

The WIRE to the device (in this case, the cigar lighter) should be protected with a fuse or c.b. of proper size. In other words, it depends on the gauge of wire which serves your cigar lighter.
As for the amp/voltmeter, the draw if very small and therefore the wire serving the cigar lighter (nee aux pwr plug) can be quite small and suffice. But, whatever gauge wire is installed.... should be protected by the appropriately sized fuse/c.b. (The original was probably a 30 A, but feel free to play it safe for the purpose you intend and install a 1 or 2 or 3 A fuse.)

George is right it depends on the wire installed. Many of these were complied with by disconnecting the wire and in some cases completely removing it. No telling what is now installed. However if it is like mine which, I think average, you will find a 14 or 16 gauge wire. I run a 10 amp fuse in mine. Low enough to protect the wire, large enough for anything I might plug into it.

The original fuse was a 20amp that was shared with the landing lights.
I'm pretty sure that's why the AD came out; lighting a cigar could blow out your landing lights.

When I re-connected my lighter (aux power) I put a dedicated 20 amp breaker on it with a 12 gauge wire. Hindsight, that was serious overkill cuz all I do it charge my iphone with it.

bagarre wrote:The original fuse was a 20amp that was shared with the landing lights.
I'm pretty sure that's why the AD came out; lighting a cigar could blow out your landing lights.

When I re-connected my lighter (aux power) I put a dedicated 20 amp breaker on it with a 12 gauge wire. Hindsight, that was serious overkill cuz all I do it charge my iphone with it.

But if if was a good cigar, you wouldn't need the landing light!

I believe the AD came out because the cigar lighter was not protected at all from Cessna.

Bruce and I belong to the mutualadmirationsociety. He's also right.

Cessna had hot-wired a number of cigar lighter installations with the only protection being a device attached directly to the rear of the socket in some cases, which does not protect the aircraft wiring from overload.

No one I know uses cigar/cigarette lighters anymore. They use the socket as an aux power supply for cell ph. chargers, GPS power, etc. etc. Most of those devices require less than 3A, and many less than 1A, which is why I suggested the quick solution above.

The 170B IPC Figure 71 (serials 20267 thru 25372) and Figure 72 (serials 25373 thru 26995)
Both show the cigarette lighter connected to the 25amp fuse that also serves the landing light switch.

bagarre wrote:The 170B IPC Figure 71 (serials 20267 thru 25372) and Figure 72 (serials 25373 thru 26995)
Both show the cigarette lighter connected to the 25amp fuse that also serves the landing light switch.

This is correct, of course, but...the wire for the cigar lighter was not appropriately sized for the 25A land lites fuse (in fact it was not identified as to gauge as it was an outside-vendor part)... the cigar lighter wire was not protected, therefore the 25A fuse for land lites was over-rated for the lighter. So Cessna/FAA-AD had it either disconnected... or separately-fused.

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