'87 A/C Died

[llangston1]

The A/C in my '87 Carrera died this past weekend. I was driving along with the local Porsche club in the 104 deg Houston heat with the blower on Hi when the A/C just quit like someone turned it off. Yesterday I was able to jump 12V power directly to the evaporator blower motor and it seemed to work fine. It ran full speed with no strange noises. I then checked the fuse panel and found fuse #2 (25A) had blown. I replaced it, turned the ignition to on and turned the blower switch to high. I could hear the blower come on and it ran for about 15 seconds when it just stopped again. I re-checked the fuse panel and fuse #2 had blown again. So what should I check next? The front condenser blower motor. Any relays? What other devices are on fuse #2 that could cause it to blow that quickly? Do I just start replacing motors and relays until the problem is fixed? Just how do you check a relay anyway? Suggestions are greatly appreciated.

[Mitch Leland]

There are 2 blowers, the evaporator blower and the front condenser blower. Did both of the blowers come on before the evaporator fuse blew? Have you looked at the A/C schematic in Bentleys?

[wwest]

First make sure the fuse holder is "crimping" the fuse TIGHTLY. Loose connection there will generate just enough extra heat to help blow the fuse.

[DRACO A5OG]

This issue is what I was CRYING about.

On HI (stage3), the fuse will blow or get so hot it will melt and as a result, shrink causing a short. No A/C

If you go to medium or low, no issues but soon as you go to high a bit later that's it. Dead.

I tried cleaning, polishing the fuse holder, bent it to put more tension on the holder even cleaning the wires to remove all corrosion. Replaced Smuggler Box Special fused Relay from Pelicans. Cleaned & Lubed both Evaporator & Front Condensor Motors, both nice and quiet. Refrigerant properly filled to spec. New Temp Control & properly positioned on Evaporator, New Dryer and all leaks fixed except the fill valve needle :-P

But still a blown/melted fuse on HI Position . I actually took a temp reading on the line at the fuse and it was freakin Hot

As recommended, I am replacing the #1 Fuse BLOCK with a New one from the Dealer and even the 2 rails with new ones, I hope this will help resolve this annoying issue.

I actually don't mind leaving it on low or med fan but would like to be able to cool down faster especially after sitting in the Sun.

Jim

[llangston1]

Would the variable speed fan switch from Griffiths fix this overheating problem or is it just the old motor drawing so much current at the high speed? Would a newer motor fix the problem?

[DRACO A5OG]

Switch will not fix the issue, an upgraded motor may.

I will post if replacing the fuse block for $21 fixes the issue.

[DRACO A5OG]

You may have to replace both evaporator and condenser motors , put a 7amp fuse on the condenser motor hot lead while you are in there. PAG added it on later models for fire safety