A/C Fuse Melts - Anyone Else Have This Problem?

[dkirk]

Interesting dillema - after much work on refurbishing the stock air conditioning system on my '88 Carrera, I was proud that the system worked well enough to make driving on hot days acceptable (to the wife). Problem now is the 25 amp, plastic core torpedo fuse runs so hot that it softens, looses contact pressure with the fuse box terminals, thus shutting the A/C system off. This happens after about 2 hours of continuous running.

The older-style fuses were made of a ceramic or porcelain core, and this is what would apparently cure this problem. Does anyone know where 25 amp fuses like this could be had? Has anyone else experienced a problem like this? Any other suggested fixes?

[86 911 Targa]

Originally Posted by dkirk

Interesting dillema - after much work on refurbishing the stock air conditioning system on my '88 Carrera, I was proud that the system worked well enough to make driving on hot days acceptable (to the wife). Problem now is the 25 amp, plastic core torpedo fuse runs so hot that it softens, looses contact pressure with the fuse box terminals, thus shutting the A/C system off. This happens after about 2 hours of continuous running.

The older-style fuses were made of a ceramic or porcelain core, and this is what would apparently cure this problem. Does anyone know where 25 amp fuses like this could be had? Has anyone else experienced a problem like this? Any other suggested fixes?

For our '86:

Make sure that the fuse contacts are clean.

It would appear that excessive current draw,
along with a series resistance can be the issue.


^^^^^
Like this?








^^^^^
Here's my fix.

This relocates some of the current draw from fuse #2 to Fuse #3.

pm me as needed.

Good luck,

Gerry

[dkirk]

Gerry,

Thanks so much for your detailed and thorough explanation. I greatly appreciate the time you took to assemble this reply. Looks to be a straightforward and logical modification. I'll try it.

[86 911 Targa]

Be sure to insulate as per this update:



Good luck,

Gerry

[gsxrken]

Power seats switches are on the same circuit. Unplug your harness under the seat one at a time to possibly ID that it is rhe seats and if ao which one.

[mkc1962]

Ive had the same thing happen ever since owning my 911. Though I also moved the small wire to another fuse to relieve some of the load I was able to find some torpedo type fuses with metal ends, identical to regular glass fuses but with tapered ends. Where? I cant remember. Yes these modern euro fuses have housings that resist zero heat.