A/C Just went DEAD, not turning on HELP

white99c2 · 07-11-2009, 02:13 PM

Drove to the supermarket, A/C worked came out and turned it on and nothing was blowing. I got home checked the compressor and its not engaging, it pretty new and I just finished a major re-do on the AC system.

What do I check, something is not telling it to come on when I turn the fan switch?

1986911 · 1986911's Garage

Check your fuse box first. Mine kept blowing fuses due to dirty terminals. The fuse would actually melt. The fusible link was intact but not making contact due to it changing shape from the melting. Its the fuse for the Blower motor.

Good luck

86 911 Targa · 03:13 PM

The previous post is correct.

I have replaced fuse #2 in the fuse/relay panel located
in the front compartment on several occasions.

This (blue) 25 amp fuse controls all of the components
in your A/C system.

Also FYI:

There are two A/C relays.

One is on your fuse/relay panel.

And the other is next to the evaporator under the pull-up
door located under the front compartment carpeting.

Good luck,

Gerry

white99c2 · 07-11-2009, 03:36 PM

No power is going to fuse number 2, the 25 amp. I jumped the compressor and it turns right on. I jumped the blower directly to 12V and it turns right on. I tried a different relay in the first relay facing the front of the car.
I cannot find a relay in the smugglers box anywhere, are we sure there is one in there? Can it be somewhere else in my '79.

86 911 Targa · 07-11-2009, 03:40 PM

If you are working on the car right now please send me an Email.

Gerry

86 911 Targa · 07-11-2009, 03:44 PM

Here is the wiring diagram for our '86.

9dreizig · 07-11-2009, 03:51 PM

I"ll bet it's the relay in the smugglers box,, it's notorious for going out

Shadetree930 · 07-11-2009, 03:58 PM

A/C ... wtf ?

Porsches have A/C?

white99c2 · 07-11-2009, 04:57 PM

There is no power to the #2 fuse at the terminal, the relay in the smugglers box clicking on and off so I'm ruling that out. As I mentioned before I can hot wire the compressor on and blower on, its not either one of those. Its some type of electrical problem.

1986911 · 1986911's Garage

The wire should have pwr at all times according to the diagram above. I figure you probed both ends of the fuse? Also make sure its #2 your are checking. The diagram on the fuse lid is confusing as to which end #1 is. If there is now power then your issue is with the fuse block. Follow the thick wire that feeds that fuse directly back to the battery. The problem has to be there.

deshetlr · deshetlr's Garage

Same simptoms as mine. I ended up replacing the ac sensor on the console. A real PITA as the replacements are not the same size as the original so a little surgery is required.

white99c2 · 07-11-2009, 10:37 PM

The red wire at the relay in the Smugglers box has no power and has no power at the # 2 fuse. I ran a new circuit to the terminal that the red wire was connected to on the relay and everything is working again.
I'm puzzled why there is no power at the fuse panel. I ran into a wall and thanks to Gerry - 86 911 Targa who spent 2 hours with me on the phone today. We were able to figure out that the issue is the red terminal on the relay has no power. Gerry wanted me to trace the wire back to the fuse panel but I took a short cut, its 113 degrees outside today and decided to run a 14 gauge wire, an inline 25 amp fuse and covered it with a conduit. It works perfectly so my issue is closed, thanks to all that responded.

p911dad · p911dad's Garage

A few years ago(7 or 8) we took the 84 Carrera down to Charlotte and then on to Charleston. The AC worked fine until on a 90 degree++ day it just quit. A call to my carologist in Corning NY suggested to look to the switch. I pulled the switch out and Ron Allison was right, the contacts were burned to a crisp. Ordered a new switch from our host and the AC worked fine. Check the switch, it has all the AC voltage running through it. I made a field fix using a small file and sandpaper to get us home.