Death of a Condenser (with Autopsy)

[zoobyshoe]

So, a few days ago I was beetling down the road, and out of nowhere, the engine started all kinds of unacceptable tomfoolery: spluttering, loss of power, misfiring, hesitation, refusal to accelerate. I pulled over and fiddled with various things for an hour or so, and ended up with it running fine again.

Couple days later, same thing again. I checked vacuum lines and the needle valve especially. After a while, I started it up, and it was fine. Later, though, on the return trip, all the problems returned: sort of a mixture of what it's like when you're running out of gas and only running on 3 cylinders. Luckily, it was down hill all the way home, and I got it back home despite the ailment. But a new symptom cropped up: on top of the other stuff, it backfired a couple times.

I got out my manuals and fired up the Samba archives, and the internet in general, and read for a few hours. Basically, everything said this could either be a fuel system or electrical problem. My points, condenser, wires, and plugs are all less than two months old, so I attacked the carb: pulled it off and sprayed out every orifice and jet 20 times. Then I put it back together and went to sleep. Next morning, when I tried to start the car, all I got was a big backfire.

More reading. I ran into reports that brand new but crappy condensers sometimes fail after a very short time. On the remote off chance I might have bought the worst brand new condenser ever, I took it out and put the old one back in.

She started right up, and 30 miles later with no return of the problem, I think that was probably it: the new condenser.

I performed an autopsy on the brand new Autozone Duralast condenser that seems to have failed and found some damning badness inside. Here is some photographic documentation of the procedure:

I cut the rolled over "lip" off the can off with a hacksaw. That's the ring around the green wire. Once that's off, I pulled out the rubber plug which insulates one end of the condenser. That's the black thing the green wire goes into.

Pull the rubber plug all the way out, and out drops a little silver "soup can" looking type thing. That is the condenser plates, all rolled up. Notice they are not soldered to anything, or even mechanically connected in any way.

Here is a shot of the inside of the can and the end of the condenser plates. They are clean and shiny: no problems here.

Here is the other end of the plates and the steel contact that is what is on the inside end of the green wire. These don't look so good.

Close up of above elements. You can see this is where the condenser fried. There has been a lot of high voltage sparking between these two things.

This is how the steel contact plate is attached to the green wire (the abrasions on the wire are from the hacksaw slipping when I cut the can open. There are similar marks on my fingers. No pics of that, though.):

Starting to unroll the condenser plates. The plates are, as far as I can tell, common aluminum foil. I miked one and it is about .0003 thick. The clear plastic insulation between the foil is about .0005 thick. There are two layers of foil and two layers of plastic. The two layers of foil are offset from each other: one sticks out about 1mm on one side, the other about 1mm on the other side. Once they are rolled up, the excess that is offset is just crushed to the bottom on the can on one end of the roll, and to the steel contact on the other end of the roll.

Here's all the intestines unrolled. I didn't find any evidence of sparking or burning inside; no insulation breakdown between the plates.

The aluminum foil (one plate or layer) is about .670 wide and about 137 inches long. That's an area of 91.79 square inches. It would be a square measuring only about 9.5 inches on a side (though it seems like it'd be larger than that from the pile you see.)

So, what this autopsy reveals is that this is very old, uncomplicated technology. The basic design of these condensers prolly hasn't changed since the 1930's when the car was first designed. Now they use plastic to separate the plates. Back then they used wax paper. It ain't no kind a fancy.

Why did it fail? I don't know. Maybe it was just manufacturing procedure: the rubber insulator wasn't pressed in far enough, leaving a poor contact between the steel and aluminum, inviting a spark to jump and burn the metal. That's plausible, but really just speculation.

Anyway, this is what is going on inside an Autozone Duralast condenser.

[Lingwendil]

Well, yup, it's just a poorly made capacitor from Autozone, thoroughly unsurprising. If the plate the wire attaches to was actually connected to the foil, and the other end was actually connected to the can, maybe it would have lasted. Bosch or Bremi tune-up parts are widely recognized as the best for a reason. I bet the contact points don't line up properly either, eh?
_________________
73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!

Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884

Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Need replacement filters for original Kadron aircleaners? WIX #42087 is a perfect fit, as is Napa Gold #2087!

[vamram]

Cool. Is German Bosch condenser the same inside, but w/the wax paper?
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[Lingwendil]

Yeah, would be neat to see how the old, and even current production looks. I'm using a ford TFI module with a Points replacement module (for now) and only have one good set of points/condenser that I'm not chopping up, but might have an old condenser on a junk dizzy i can dig out...
_________________
73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!

Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884

Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Need replacement filters for original Kadron aircleaners? WIX #42087 is a perfect fit, as is Napa Gold #2087!

[Cusser]

1. Autozone did not manufacture that condenser.

2. My two German-made 009 distributors are still running their original condensers, 4 decades in !!!
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[Mojo07470]

The biggest reason VW,s are unreliable and performance is poor. All the parts today are junk I don't care where you buy them they're junk. Carbs distributers mufflers fuel pumps. None of these items work as they should. I went to electronic ignition. I figured if I could carry points and condenser well, I could just carry a spare module. Theres nothing wrong with points and condenser If you can get quality parts.

[Dwayne1m]

I've had 2 breakdowns with my Beetles and both times it was because the condensers took a crap, and both were relatively new Bosch condensers bought from reputable vendors, so I'm not convinced that Bosch condensers are any more reliable. Personally I would be willing to pay double the price for quality reliable parts but I don't know of anyone out there that sells them. I also had 2 new Bosch alternators that were junk as soon as I took them out of the box, so don't think that just because the name "Bosch" is on the part it's good.

And thanks for dissecting a condenser. Interesting.

A little tid bit on how a business works. The vendors do not make the parts. They buy the parts from a business that makes the parts. Chances are very good if you buy a part from any vendor that part was made by the same place. For instance, I bought a front tranny mount a few years ago but the studs for the front were to short and I couldn't use it. I checked with every vendor for the mount with the correct length studs but they were all short studs. One vendor finally admitted to me that there is only one company that makes these mounts so no matter where you buy them it will be the short studs.

[vamram]

[kreemoweet]

http://www.nonlintec.com/sprite/cap_failure/
_________________
'67 bug: seized by the authorities
'68 bug: seized by the authorities
'71 kombi: not yet seized by the authorities

Stop dead photo links! Post your photos to The Samba Gallery!

[adam78]

hmmm Im having those exact symptoms, and I just got finished completely redoing my carb, changing vacuum lines, and replacing the vacuum plugs trying to figure out why...and I did replace the condenser as preventative maintenance a few months ago...Now I know if it's not broke dont fix it! I'll be throwing an electronic ignition in it and be done with it. It did wonders for my bus and runs great.
_________________
1975 Beetle 1600dp 4spd Daily Driver.
1972 Westy 1600 Type IV 4spd project/ soon to be driver.

[wcfvw69]

Autozone is the absolute worse FLAPS joint out there. I don't think they sell much of anything that's not made in China. They are the Wal-Mart of parts resellers. I don't shop at Autozone.

Napa still sells good parts and I don't mind paying more for them either. There are lots of reports of folks running original Bosch made condensers for decades w/no issues.

I bought a used original Bosch DVDA distributor and took it all apart to clean, inspect and re-lube it. It had clearly not been used in years though it was stored inside. It had original Bosch points and condenser in it that look to have been made in the 70's. The points block had lots of life on it still and the points only required a file. I put them both on the rebuilt distributor, greased the points cam and they work like new.

There have been lots of reports of brand new Bosch condensers shitting the bed right away. I think this is why many VW veterans are running old condensors.

Bosch parts use to be a quality name but now there parts for classic VW's should be looked at with suspicion.
_________________
Contact me at [email protected]
Follow me on instagram @sparxwerksllc

Decades of VW and VW parts restoration experience.
The Samba member since 2004.

**Now rebuilding throttle bodies for VW's and Porsche's**
**Restored German Bosch distributors for sale or I can restore yours**
**Restored German Pierburg fuel pumps for sale or I can restore yours**
**Restored Porsche fuel pumps or I can restore yours**
**Restored Porsche distributors or I can restore yours**

[sb001]

[davidw99]

[Brian_e]

I have lost a few new condensers in the last few years. Last one was a week ago with less then 400 miles. It was a genuine Mallory one too.

Here is a trick I learned from an old timer.
Next time you think you have a bad condenser, and have the symptoms listed above, grab a pair of pliers form your tool bag, and smash the condenser. Just pinch it tight. I have done this, and almost every time it will get you home. Also helps your trouble shooting.

Upon your return home, contact your favorite retailer and order a Pertronix module. Some people think they fail all the time, but these days, they seem to be failing way less then a brand new condenser.

Brian

[Old n' slow]

[wcfvw69]

[zoobyshoe]

[Old n' slow]

[zoobyshoe]

[busdaddy]

If you were to stick the wire through a hole in the workbench or a plate and give the can a moderate whack to increase the crimp action it may temporarily improve the rubber to contact squish factor, just trying to think of a suitable anvil when doing this roadside. A wheelnut would work on a bus, but not so much on a bug, lug hole in the spare maybe?
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!