1997 850 10A cig lighter not enough for appliances?

[BEJinFbk]

I just noted on that fuse legend file that the cigarette lighter is shown rated at 15amp ?
Item 30 on the list.

item. 35 is for the cigarette lighter illumination and is rated at 10 amps.

Front/Rear.
I think 30 is the front.
I'll have a look later if
no one beats me to it.

[BEJinFbk]

Yup - Going by the diagrams, the front appears to be protected to 15 amps on fuse 30.
Couldn't find confirmation that the rear is on fuse 35, but if I find it, I'll post it.

[BEJinFbk]

1-1/2 YEARS LATER - UPDATE:
The cig lighter at the rear of the center console
is the only item I see in the diagrams on Fuse 11C/36.
Like the front cig lighter on 11C/30, it's fused at 15 amps.

98 S-V70 Cig Lighter .pdf

(485.28 KiB) Downloaded 183 times

EDIT - I just noticed my mistake - I've posted 70 series info
rather than '87 850 information. My bad - But good 70 info!
And since the 850's haven't got the rear outlet...
My Apologies.

[MrAl]

Hello there,

Just some notes on wires, fuses, heating, etc.


As you know by now, fuses are there to protect the wiring and possibly the devices plugged into the outlet.
The fuse ratings are chosen based mostly on the temperature rise of the wire in question. The temperature rise affects the insulation of the wire as well as the voltage drop caused by that wire.

If the temperature goes up too high, the insulation melts. If the insulation melts, the wire could short out and cause a permanent problem where the circuit can no longer be used at all.
Also, the voltage drop across the wires to and from the outlet will go up, which reduces the power to the device plugged in. That has both positive and negative effects. Negative in that the device may not operate as well, and positive in that the reduced voltage tends to reduce the current draw a little, which in turn eases up on the wire temperature rise a little.

The temperature rise does not happen immediately however. It takes time for the wire to heat up. Unfortunately the wire is always insulated, and that means it is insulated electrically but that also has the side effect of being insulated thermally as well. That means that the wire will heat up slow, but not too slow. Since 15 amps over 10 amps is a 50 percent over current, it probably wont take 'too' long for the wire to heat up, but there will be a finite time that it takes to get to a dangerous level. Therefore if the run time of the device is kept low the wire will always survive, even if this process is repeated many times, as long as the wire is allowed to cool each time before the process is repeated.
This is rather hard to predict, and so if the fuse is made larger by 50 percent then there are other things that could happen, such as a user gets in the car and uses it for two hours at 14 amps, and burns the wire insulation. This means a timer would also be a good idea.

A safer way to go is just install your own. In my old Hyundai i had at one time installed a bank of 3 cigar outlets with a fuse rated for 30 amps. The wire was run directly from the battery terminals right to the bank of outlets with heavy enough wire to handle the load, and of course the DC fuse, which was an inline fuse holder and 30 amp blade type fuse which came from Radio Shack. I rarely get stuff them them anymore but they had one so i bought it
Something like that does the trick and then some.

Of course the adapter is the fastest and easiest way to go. I have a heavy duty one that i use now. An alternative is to cut the cigar plug off of the air pump and connect two light duty large alligator clips to the very end of the wire where the plug was. That allows you to simply clip it on the battery without needing the adapter. Works nice too and the light duty alligator clips are not expensive, although i did solder mine on, which requires a heavy duty soldering gun.

Let us know what you end up doing for the long term if you can.