Help for HVAC Problems

For full access to the "hidden fuse", you have to remove the trunk liner, which isn't difficult. But it's possible to lift the rubber seal up from the right rear (passenger) corner of the trunk compartment, then lift up the corner of the liner itself, and look inside. You're looking for the two light green relays, side-by-side. Just to the front of these is the fuseholder for the 30amp fuse that controls the climate control system. The original fuse was a blade type, many of these have been updated to "bullet type" glass fuseholders with far more contact area.

Edit: And welcome to Ferrari Chat!
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http://webpages.charter.net/aircover/348/1994Ferrari348Spider.html#AirConditioning

 

Good idea. Keep 'em coming. Most of Miltonian's contributions add to that web page, anyway. Wait until you see the infamous pool cue...

 

I just changed the "hidden" fuse today.
The blower in the 355 stopped working a while back, so no heat or AC. Had checked the fuse panel and everything was ok. Then lifted the trunk liner to see a green melted fuse. Changed it and the system now works as it should. I will look into changing over to the newer bullet style fuse.
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Isn't that a kick in the fanny? And Ferrari persisted with that inadequate design for years and years. And they placed the fuse where you can't see it and can't get at it without pulling the trunk lining! And (at least on the 348) they don't bother to tell you in the Owners Manual where the fuse is located!

 

Very disturbing isnt it?

 

Well, I've now blown 2 new fuses. The blower doesn't last too long, maybe 2 minutes, before the fuse blows and everything stops working again.
Hard to believe simply changing to a different type of fuse would solve it. Either way, there are 30 amps going through the circuit.
Anybody have a final solution to this? I'm freezing in the mornings and burning up during the day!

 

If it's actually blowing a 30amp fuse due to a short, rather than melting the fuse due to excessive resistance, then you might try looking at some of these things:

- Is there any evidence that the wiring insulation in the vicinity of the 30amp fuse has melted and may be touching a ground?

- Does the blower fan spin OK by hand? There are no obstructions in the fan housing?

- Does the fresh air recirculation flap appear to be free to open and close?

- Is it possible that some accessory has been tapped into the electrical wiring to the climate control system (stereo/alarm/radar detector/etc)?

- Is it possible that a mounting screw for some accessory has penetrated a wiring bundle and shorted a wire to the climate control system, either in the trunk or in the dash/console?

Good luck, let us know what you find.

 

Thanks for the input.
I will try to check all of those things. May be easier to remove the whole trunk liner to get to the whole system.

 

Good things to check, but you still want to switch over to the bullet-style 30 amp fuse.

 

I do plan on doing so, but I don't see why any 30amp wouldn't blow when 30amps are put through it. Shouldn't matter what style of fuse.
There's an overload somewhere, just need to find it. Shouldn't be more than 24 continuous amps in the circuit.

 

The style matters because excess heat can increase resistance, which in turn lowers voltage, which then requires more current to obtain the same power. More current (amps) blows fuses.

The bullet fuse dissipates heat better, minimizing this problem.

In contrast, the non-bullet style (a Ford piece, actually) has exterior plastic that tends to melt onto the fuse metal. This can happen even if the fuse itself doesn't blow (at first).