Fire - and the front condenser blower

[mulligan101]

To quote John Walker ...."then there's the front condenser blower that catches fire........"

Too bad I didn't see that post, or others about the front condenser blower, earlier.

Last Sunday was a nice day. Not too hot, but I thought I'd run the AC for just a little bit in order to give all the parts a chance to move. Silly me. A couple minutes later I saw smoke from the dash. I pulled over, shut everything off, and waited for the smoke to stop. It didn't. It got stronger. So I pop the front hood and search the bulkhead area for where the smoke was coming from. I should have looked down. When I did, I saw flames erupting from the battery area. I grabbed the fire extinguisher and let loose with more spray than I probably needed (plus a few bursts just for good measure - it's not everyday I see my car burn).

The flames burned the trunk carpeting and melted two quart bottles of oil (yep, oil all over the front of the car). I disconnected the front condenser wires, made sure nothing else was smoking, started up the car, and drove home. Once home, I addressed the damage. In addition to the melted carpet, the blower was a plastic blob, the battery has a nice bulge in it, and rubber/plastic soot covered the bottom of the hood.


Melted carpet....


It's seen better days....


Cleaning out the trunk....


The trouble maker....


It must have gotten pretty hot to do this......


Still cleaning.....

Since last Sunday, I've read all I could about the front condenser blower. It seems that some of our cars were installed without a fused connection to the blower. Boy, was I pissed when I read that. But what was that thing on the wires. A quick check of the charred remains of the blower seems to show that I had a fuse!


Sure looks like a fuse....

What the heck?!?

I guess it could have been worse. I've replaced the battery, gone thru a bottle of Simple Green, and decided I can do without AC for while. Next task...get the fire extinguisher recharged.

Check your fuses. Check your blower motors. Safe driving everyone.

-------------------
'88 Carrera

[Wil Ferch]

I think the quote may have come from me....I'm quite sure I said that.

No....the Porsche flying fuse that was put there for the 87 or 88 cars and later....was a 7.5 Amp USA style blade fuse....not the German suppository style.

Dumb Germans....they didn't put in half the fuses that are required.....nice charring of the (ahem )...*fuel tank* ( !!!!!!).....

But, your sign-off says you have an 88...shoulda had one from the factory !

[Biff]

This happened to me as well last Saturday morning but as soon as I smelled the fuse blow I pulled over and the fan was really hot. I pulled the plug that supplies power to the fan and it was a hot one hour ride home with no AC. The charred gas tank is scary. In my youth traveling on the PA turnpike in the summers with my family I have vivid memories of VW bugs along side the road either smoking or on fire with the owner just standing there watching. I alway carry a halon fire extinguisher.....guess where mine was stored last Saturday? Right beside the condenser fan!

[DRACO A5OG]

OMG! That is scary $H!T!

My AC fuses always gets so hot that it melts and shrinks and causes the fuse not to have contact causing a short in the system.

This only happens when I use the 3rd level on the switch. Could my Condensor be binding or going out?

[schumicat]

You're lucky it wasn't worse. This is one problem I won't have (no a/c). Why do you need a/c in Seattle anyway? Just roll down the windows and open the sunroof.

[KNS]

Pelican sells the fuse kit: 911.612.077.00, For the front condenser fan.

[DRACO A5OG]

Originally Posted by KNS

Pelican sells the fuse kit: 911.612.077.00, For the front condenser fan.

It seems like the wrong number, I guess we can place a fuse on that hot line, right?

[KNS]

911.612.077.00 is the right number, I've got it installed in my car. It might be labeled "Chassis Harness" or something in the catalog.


Edit: Sorry, it's not in the catalog but a special order part.

[dsmyth]

Kurt Tried the number above on Pellican and cant find a reference?

[ratpiper71T]

Wow! Thank god it wasn't worse! And that you caught it in time...

[canamfan]

Thankfully you caught it before it went real ugly! I wonder....if there is a better way, motor/blower set up. This is a very common& dangerous problem. I for one am too reluctant to put back the original set up just because I'm not confident in this old mouse wheel electrical set up. Do we have any other options?

[m110]

Am I understanding that 88s came with the fuse from the factory and don't need anything else?

That is frightening.

Glad you're safe.

There was a recent thread about the best fire extiguisher...not halon if I remember but something newer...anyone know?

[dshepp806]

What actually happened here, being that it was fused? Can this damned thing go up in flames without generating an overcurrent condition (for the FUSE)??????????????

WOW!

Doyle

[m110]

Not to hijack but the fire extinguisher topic is important; here is an excerpt by lucittm from this thread:

What is the best type of Fire Extinguisher?

OK, something I know a little bit about.
First, no fire extinguisher does everything well, you have to figure out what the goal is.
Hint: electrical conduction fires "C" are usually not serious if you can remove the power. The exception is if the electrical fire causes another type of fire. Fires that leave an ash "A" are pretty easy to put out and if you are working on a car fire type "A" materials are carpets, seats, and human beings (we used to call them screaming alfa's). The biggies are flammable liquids "B" and flammable metals "D". The liquids are oil and gas, of course. The metal is magnesium. We have engine parts made of magnesium and there is no way to put out a metal fire because they make their own oxygen and they are very hot.

Second, let's concentrate on liquid fires, the ones that destroy our cars. Aqueous Film Forming Foam (AFFF) is the best but very hard to carry around in the car (that was mentioned before). Also, it has a shelf life and you need enough to prevent a re-flash. I have seen a guy step in a puddle of it and the fire erupted when he lifted his boot. Finally, it has no use on electrical fires and almost useless on type "A" fires. The gases: CO2, Halon, and water fog spray work pretty well but you have to get the fire completely out at close range and hope the surfaces are cool otherwise Poof, a re-flash.

Third, what to use? Powder, but not just any powder. Baking soda works in the kitchen but sodium bicarbonate is not very good at removing the oxygen (smothering) it is slightly better than salt. So we want something that smothers the fire, does not conduct electricity, and not as corrosive as some other agents. General purpose dry chemical extinguishers use monoammonium phosphate, nasty stuff. So, use what the Navy uses on their ships, Purple K Powder (PKP) or potassium bicarbonate.

From Wikipedia:
"Purple-K is a dry chemical fire suppression agent used in some dry powder fire extinguishers. It is the most effective dry chemical in fighting class B (flammable liquid) fires, and can be used against some energized electrical equipment fires (USA class C fires). It has about 4–5 times more effective against class B fires than carbon dioxide, and more than twice that of sodium bicarbonate. Some fire extinguishers are capable of operation in temperatures down to −54 °C or up to +49 °C. Dry Chemical Powder works by directly inhibiting the chemical chain reaction which forms one of the four sides of the fire tetrahedron (Heat + Oxygen + Fuel + Chemical Chain Reaction = Fire). To a much smaller degree it also has a smothering effect—excluding oxygen from the fire."

I have a 10lb bottle of PKP in my car (it fits on a Brey-Krause mount). If you ever have an engine fire, you will be glad if I pull up behind you because I have a 20 foot range and 24 seconds of discharge time. You can get PKP extinguishers at places like this:
Amerex 10 lb Purple K Fire Extinguisher
and
Ansul Sentry 10lb. Purple K Fire Extinguisher - Monroe Extinguisher

More expensive that a 2.5 lb can of baking soda, but inexpensive insurance to me.

[rnln]

I still don't understand. The car has a fuse there, he found. Why isn't the fuse burned?

[dshepp806]

Ditto! Something's amiss.................(and it could be that this system can start a fire from a friction-based failure without pulling more current than the circuit fuse......I find this hard to believe, but am open for info from the REAL P-wrenches out there.


Doyle

[suprxman]

I bought my SC last fall and it had the AC compressor removed. During my winter projects I pulled the condenser blower. Tried to turn the squirrel cage and discovered that either the motor or the cage was VERY hard to turn. Took it off and made an aluminum plate to cover the hole. When I restore the AC system I will either repair or replace the whole thing. Check your out. It's obvious when it's too tight to turn. Not a 10 minute job.

[DRACO A5OG]

I serviced mine after hearing a whirling noise up front when AC was turned on.

It was pretty sticky, but I still get that fuse block really hot at stage 3, has anyone swapped a fuse block to fuse block within the same panel, i.e. 8 amp fuse block with 25 amp fuse block?

I do not mean the fuse itself but just the block with spring clip.

[tchanson]

Originally Posted by m110

Am I understanding that 88s came with the fuse from the factory and don't need anything else?

I don't believe the factory added the inline fuse until '89 3.2's were in production.

A TSB was issued in 8-88 (#8803) that outlined the addition of a 7.5 amp fuse to the power cable going to the condenser motor.

The fan power is normally switched on by a relay and an independent lead straight from fuse 20. As that fuse is hot all the time, a stuck relay could run the fan continuously, which may cause it to fail.

The TSB refers to the revised, fused wiring harness (which is shown above correctly as #911.612.077.00) which can be easily retrofitted to all pre 8-88 cars.

Not sure what happened above, but that inline fuse does not look like the fuse or harness that was installed by the factory on '89 cars.


Tim

[DRACO A5OG]

So I can add any kind of 7.5 Fuse at the hot lead of the motor?