Hello, world! I've had a problem with my ignition condenser blowing. I replace it, and the car will start. Sometimes it runs for a few seconds and dies, other times it will run for 5-10 minutes before it quits. My readings on this issue lead me to believe that it's a bad/dying alternator. I no longer have the ability to do much work on the car myself, and therefore have to take it to a shop. (yeah)

Two questions:
In your opinion(s) does this sound like an alternator problem?

If so, other than the alternator itself, what other parts do I need to provide to the shop so they don't get it all opened up and discover they need them and have to wait for more deliveries?

Thank you in advance!
-R

Very rare for an ignition condensor to go bad. I read your description of trouble shooting but that doesn't really prove anything. Sounds more like coincide of occurrence than any sort of direct correlation.

A condensor is just a capacitor - It blocks DC voltage and grounds AC transiient spikes that result from EMF when the points open/close. A condensor prevents the points from burning over long periods of time. A condensor is not likely to go bad or be related to the alternator. Not sure how you made that leap What testing did you do with the condensor to determine it is indeed bad or blown?

Have you measured voltage at the battery when the engine is running? That would be 1st step if you suspected an alternator and/or voltage regulator problem.

You need a shop that can do basic electrical troubleshooting and they should not just be part swapping hoping for a fix.

Are you asking about diagnosing the problem or are you asking about taking a buffet of parts to your shop?

have you measured voltage when the car is running?

Hi Randy:

Overvoltage condition from a jump start or a current surge from an alternator failing while running. Plus shock, vibration, and temperature extremes, sounds like NY to me.

Good luck

I have replaced the condenser in this car at least a dozen times over the 8 years I've owned it. As the poster below mentioned, this can be due to spikes coming from a failing alternator. This is consistent with what I have read elsewhere when trying to research why the condenser would keep failing. Unfortunately, I no longer have any of my tools/meters, and have no space in which to work on the car, so no, I have not tested voltage. How did I arrive at the condenser being bad? Easy enough! Car won't start, cranks and cranks, gets gas, no spark. swapped coils. same thing. swapped condensers, presto! In the past, this might have been an annual occurrence. Now it keeps popping. Replace condenser, it starts again, but only runs for a short period then dies. Replace again, same thing. SOMETHING is causing it to repeatedly fail. Thankfully, they're cheap.

I'm asking about both! The alternator is the most logical issue to me, and I'm concerned that if I drag the car to my shop with a new alternator to install, they'll open it up and discover 3 or 4 other parts that need replacing as well due to age. Thought you guys could save me the headache of waiting for further parts shipments. My shop is clueless about getting parts for 914's. They do, however, do good work.

Overvoltage from a jump sounds about right! As I mentioned above, it's almost an annual thing. My battery does drain if the car sits too long, since I don't know how to properly install a stereo head unit, amplifier and speakers! In order to start the car right now, it must be jumped. With a new condenser, it will pretty much fire right up, but only run for a maximum of 10 minutes, usually less than 2.

Is it possible that my ground strap is shot enough to cause electrical turbulence that might pop a condenser? I did have to replace a badly stretched out clutch cable a few years ago. I've heard they can stretch due to heating because they're being used as a ground?

Easy enough to check the ground.
You might try charging the battery fully, disconnect the alternator at the relay plate, does the condenser fail before the battery dies? Run the car with as little electrical load as possible.

Like so many threads with electrical gremlins, this is going all over the map. Without tools and a desire to troubleshoot the problem to root cause, allow me to reiterate:

You need a shop that can do basic electrical troubleshooting and they should not just be part swapping hoping for a fix.

@mgphoto
This is NOT recommended. Do not disconnect and run the alternator when disconnected from the battery

Directly from Haynes (Alternator testing in-situ) section 8:
"Precaution - never run the alternator with the battery disconnected."

Here is the recommendation from the factory service manual
Click to view attachment

The battery (or load bank) serves as a load and a ripple filter helping to preserve the alternator rectifier diodes.

I believe you are mistaken, disconnect the alternator, no damage at all to the car and it will run for about a half hour without much load. I never said disconnect the battery.

@mgphoto

By disconnecting the alternator at the relay plate, the alternator is being run without regulation - agree B+ is still connected to the battery.

You're risking damage to the alternator rectifier diodes by removing voltage regulation. My or may not happen instantaneously. Why take the risk to troubleshoot a condenser problem is my point. Condenser is easily tested with an analog Multi-meter. Battery voltage is easily tested with any cheap DMM. Ground connection are easily tested with DMM. No need for the risk.

I'm not here to argue, or meaning this as a personal attack. I've cited two reliable sources that caution is warranted.

So start the car with the alternator disconnected, we are trying to diagnose a problem.

@Superhawk996
Eject Eject Eject

To go back to the condenser problem:

Other things that can lead to a condenser failures:

Condensers are electrolytic capacitors. You don't want NOS parts. Electrolytic capacitors can dry out and go bad due to age. What you want are NEW condensers.

Condensers can be damaged by running a "hot" coil that develops more EMF than OEM coils.

Condensers can be damaged by running a coil without a ballast resister. OEM coils have a 3.2 ohm internal ballast resistor.

You want a condenser designed for the Bosch coils with the internal ballast resistor. I don't know what condensers OP is using. I'm assuming proper condenser but there was no info posted so who knows.

Points gap set too close. This leads to a strong desire for the points to arc and means that the condenser must work very hard (i.e. flow more current due to EMF / AC transients) than design intent.

Yes - I read OP swapped coils as part of his diagnostics but again, I have no idea what coil was swapped for what. Could have two "hot" coils, two without ballast resistors, or one that works (on the car) and one bad (the spare that was swapped). Who knows

Again point being, OP better served to have shop that is competent at basic electrical diagnostics look at the car.

LOL - agree

Points and condenser are archaic by today's standards. There are many solid state points that are drop in replacement and you never have to deal with condensers again.

Whatever is smoking the condenser probably wouldn't be good for a 123.


Although getting the right coil for a 123 might help some. Have you got a multimeter?