What fuses are in Fuse Box III?

[tasturbo86]

As shown in this picture, my '86 911 turbo has had some HOT wires going to this fuse set. I'm looking for a description of what those 3 fuses control, so I can find out what is going on.
I'm wondering if the old style fuses in the fuse block have such poor connectivity that they cause the heat?

[aj88cab]

The top fuse with the two wires is probably for the engine blower, but the diagrams I have seen indicate the middle fuse is for the engine blower. The engine blower is a 25A fuse, and definitely has a two wire feed.

So in this case the middle fuse appears to be the footwell blowers (0,1,2 speeds if manual). The high speed (#3) is feed from the front trunk fuse panel. It should be a 16A fuse here & 25A at the front.

You should trace the circuits to be sure, but possibly the top & middle fuses were switched during a repair or something, or that's the way the Turbos were done..

Both of these would run through the fan controller module on that same relay rack, silver box visible to the right in your picture.

The bottom fuse is rear window defogger & wiper.

[tasturbo86]

Thanks!

I replaced the portions of the wires that were black, partially for cosmetic reasons. I'll watch them when I get the engine back in.
None of those things are important to me, so if they get hot again, I will be pulling the fuses.

terry

[aj88cab]

As those fans age they start pulling more current, so it might be an indication the fans are on their last leg. Porsche added in-line fuses at the individual footwell blowers in 1987 (maybe '88) to protect against just this kind of issue.

[john walker's workshop]

Turbos don't have engine fans.

[aj88cab]

Thanks John!
And that is my "learned something new today" lesson