Another Front Condensor Fan Bites the Dust

[targa80]

I have been testing the AC system for leaks before I reinstall the system in the car.


The system holds a solid vacuum and I have ordered a new Dryer to install once the system is back in the car. The next step was to check the two fans (Evaporator and front Condenser) . The Evaporator fan needed a little lube on the two bearings since it was hard to turn initially. The Front condenser fan was frozen and when I took it apart this is what I found.

The brush mountings melted to the commutator


You can see one of the Brushes in the picture.


Looking at the AC circuit, it is protected with a 20 amp fuse in slot 20 and I don't remember it being blown. As an added precaution, I will be installing an in-line fuse with a lower amperage rating for the new motor.

[Rodek]

Sorry to hear about the motor biting the dust and I hope your new motor gives you years of trouble free A\C. BTW, nice tip on the fuse. I think I'll do the same once I get that hose taken care of.

[shadowjack1]

As I recall that new inline fuse should 7.5 amp.

[GH85Carrera]

That fan is the cause of a LOT of 911 fires. There is a Porsche part number for a inline fuse that is part of a recall.

[Dueller]

I think I have two of those motors if you need one. One is NIB if I recall. Let me know.

[cabmandone]

Wow! 20 amp? Is that what is called for in that circuit? It seems like the suggestion of a lower amperage fuse inline is a very good idea.

[Barrpete]

Originally Posted by shadowjack1

As I recall that new inline fuse should 7.5 amp.

+1, 7.5 amp is correct.

[MConn]

If you don't want to cut your harness, the Porsche part number for the inline fuse is 911612077 - kind of pricey

I think I had to use a 10 amp because of starting current, but I'm using a footwell blower motor.

Mike

[ganun]

BTW, a cool idea to lay it all out like you did and pull a vacuum. Now all you need is to hook the comp to a 5 hp elec motor and put the evap in its box ........

[ganun]

I forgot to mention that the evap blower should be replaced if it was hanging up, even if you freed it up and it rotated better it still won`t run at the revs as a new one.

[86 911 Targa]

HOPE THIS HELPS.

[Rodek]

Alright, since I'm still learning my 911 and it's A/C system, I have to ask. Where is this inline fuse supposed to be located? The smuggler's box or the in-trunk fuse holder or....somewhere else???

[targa80]

Originally Posted by Rodek

Alright, since I'm still learning my 911 and it's A/C system, I have to ask. Where is this in-line fuse supposed to be located? The smuggler's box or the in-trunk fuse holder or....somewhere else???

rodek,

if i remember correctly you said you did not have the front condenser with the fan. the fan on the evaporator in the smugglers box is protected from the elements of outside air on the other hand the front fan draws air directly from the environment and is drastically effected over time. i would not go with a separate fuse in-line for the evaporator fan but that's just my thought process, others may disagree. you are lucky to have an uncle with the vacuum pump and i bet he has the gages too. if not i bought the gages anf the 2.5cfm vacuum pump from my local harbor freight. yes, they are made in china and they are cheap but for a diy shady tree mechanic they fit the bill for my limited use. did i mention that they are really cheap.

[targa80]

Originally Posted by cabmando

Wow! 20 amp? Is that what is called for in that circuit? It seems like the suggestion of a lower amperage fuse inline is a very good idea.

looking at the schematic for the a/c circuit fuse 20 is rated at 25 amps, understand this provides power to all of the electrical elements of the a/c system.

[targa80]

Originally Posted by Dueller

I think I have two of those motors if you need one. One is NIB if I recall. Let me know.

jim,

thanks for the offer but i have one on the way from our host.

[Rodek]

Originally Posted by targa80

rodek,

if i remember correctly you said you did not have the front condenser with the fan. the fan on the evaporator in the smugglers box is protected from the elements of outside air on the other hand the front fan draws air directly from the environment and is drastically effected over time. i would not go with a separate fuse in-line for the evaporator fan but that's just my thought process, others may disagree. you are lucky to have an uncle with the vacuum pump and i bet he has the gages too. if not i bought the gages anf the 2.5cfm vacuum pump from my local harbor freight. yes, they are made in china and they are cheap but for a diy shady tree mechanic they fit the bill for my limited use. did i mention that they are really cheap.

Thanks for clarifying! I don't have a front condenser so I guess the inline fuse doesn't apply. Yes, I'm glad my uncle has the vacuum and you're probably right about him having the gages. I may go ahead and pick my own set up at harbor freight just to have them around for my other vehicles too. It's not a bad idea to pick up that vacuum I suppose as well.

[86 911 Targa]

Originally Posted by Rodek

Alright, since I'm still learning my 911 and it's A/C system, I have to ask. Where is this inline fuse supposed to be located? The smuggler's box or the in-trunk fuse holder or....somewhere else???

This fuse holder located on the fan harness
was added on the M/Y 88-89 on a Porsche service bulletin.

Fusing for the 3.2 cars was not Porsche's finest hour.

Check my threads/posts for added fuses and relays.

Or, pm me.

Good luck,

Gerry

[Jack Stands]

Those brushes looked a lot like mine when it stopped working. A new motor ( I think sourced from eBay), and an inline fuse and I'm good to go.

There are threads on replacing the condenser fan, just be careful removing the blower fan off the motor shaft.

[Discseven]

I had same melt down with mine.



A follow up on Jacks note about removing blower... the allen screw securing blower to shaft on mine was sealed with some sort of hard wax. I'm not drilling it out in the photo below... I'm just poking the stuff with a drill bit... and it came out. The blower took some time getting off the shaft.

[Jack Stands]

Once you loosen the Allen head sets crew, getting the squirrel cage blower off the shaft can be a chore. As the motor is toast anyway, I found it easiest to chuck the motor housing in a vice and tighten down until the housing is distorted enough to crush the armature against the outer housing, preventing it from turning. Then by simply rotating the outer edge of the fan blades, I was able to turn the entire shaft so as to get it to break away from the commutator and electrical windings, then simply remove the shaft with the fan attached. Then, it was simple to rest the hub of the fan supported on a vice and simply tap the shaft out of the hub with a drift.

When you install the new motor and fan assembly, check the positioning of the fan in the blower housing so it doesn't hit or rub against the plastic.